CVE-2021-31806

mediumpriority · attend · 69EPSS 0.953 · 100 %ileexploit · functionalDEEURUUS

grimoire priorityP1 · Urgent

Exploitable?

Public exploit

1 exploit · functional

Likely / severe?

95.3% (100th) EPSS

CVSS 4 · medium

Is it mine?

62 products

Check your exposure

Who says so?

6 sources

cnnvd · enisa_euvd · fstec_bdu · osv

EPSS · scored 2026-10-26

An issue was discovered in Squid before 4.15 and 5.x before 5.0.6. Due to a memory-management bug, it is vulnerable to a Denial of Service attack (against all clients using the proxy) via HTTP Range request processing.

remediations

Vendor fix, mitigation, or workaround guidance, as published by each source.

A vendor fix is available.

Fixedlibecap-0:1.0.1-2.module+el8.1.0+4044+36416a77.aarch64 (squid:4) as a component of Red Hat Enterprise Linux AppStream (v. 8)redhat_csaf
For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 After installing this update, the squid service will be restarted automatically.
https://access.redhat.com/errata/RHSA-2021:4292
Fixedlibecap-0:1.0.1-2.module+el8.1.0+4044+36416a77.ppc64le (squid:4) as a component of Red Hat Enterprise Linux AppStream (v. 8)redhat_csaf
For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 After installing this update, the squid service will be restarted automatically.
https://access.redhat.com/errata/RHSA-2021:4292
Fixedlibecap-0:1.0.1-2.module+el8.1.0+4044+36416a77.s390x (squid:4) as a component of Red Hat Enterprise Linux AppStream (v. 8)redhat_csaf
For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 After installing this update, the squid service will be restarted automatically.
https://access.redhat.com/errata/RHSA-2021:4292
Fixedlibecap-0:1.0.1-2.module+el8.1.0+4044+36416a77.src (squid:4) as a component of Red Hat Enterprise Linux AppStream (v. 8)redhat_csaf
For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 After installing this update, the squid service will be restarted automatically.
https://access.redhat.com/errata/RHSA-2021:4292
Fixedlibecap-0:1.0.1-2.module+el8.1.0+4044+36416a77.x86_64 (squid:4) as a component of Red Hat Enterprise Linux AppStream (v. 8)redhat_csaf
For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 After installing this update, the squid service will be restarted automatically.
https://access.redhat.com/errata/RHSA-2021:4292
Fixedlibecap-debuginfo-0:1.0.1-2.module+el8.1.0+4044+36416a77.aarch64 (squid:4) as a component of Red Hat Enterprise Linux AppStream (v. 8)redhat_csaf
For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 After installing this update, the squid service will be restarted automatically.
https://access.redhat.com/errata/RHSA-2021:4292
Fixedlibecap-debuginfo-0:1.0.1-2.module+el8.1.0+4044+36416a77.ppc64le (squid:4) as a component of Red Hat Enterprise Linux AppStream (v. 8)redhat_csaf
For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 After installing this update, the squid service will be restarted automatically.
https://access.redhat.com/errata/RHSA-2021:4292
Fixedlibecap-debuginfo-0:1.0.1-2.module+el8.1.0+4044+36416a77.s390x (squid:4) as a component of Red Hat Enterprise Linux AppStream (v. 8)redhat_csaf
For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 After installing this update, the squid service will be restarted automatically.
https://access.redhat.com/errata/RHSA-2021:4292
Fixedlibecap-debuginfo-0:1.0.1-2.module+el8.1.0+4044+36416a77.x86_64 (squid:4) as a component of Red Hat Enterprise Linux AppStream (v. 8)redhat_csaf
For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 After installing this update, the squid service will be restarted automatically.
https://access.redhat.com/errata/RHSA-2021:4292
Fixedlibecap-debugsource-0:1.0.1-2.module+el8.1.0+4044+36416a77.aarch64 (squid:4) as a component of Red Hat Enterprise Linux AppStream (v. 8)redhat_csaf
For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 After installing this update, the squid service will be restarted automatically.
https://access.redhat.com/errata/RHSA-2021:4292
Fixedlibecap-debugsource-0:1.0.1-2.module+el8.1.0+4044+36416a77.ppc64le (squid:4) as a component of Red Hat Enterprise Linux AppStream (v. 8)redhat_csaf
For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 After installing this update, the squid service will be restarted automatically.
https://access.redhat.com/errata/RHSA-2021:4292
Fixedlibecap-debugsource-0:1.0.1-2.module+el8.1.0+4044+36416a77.s390x (squid:4) as a component of Red Hat Enterprise Linux AppStream (v. 8)redhat_csaf
For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 After installing this update, the squid service will be restarted automatically.
https://access.redhat.com/errata/RHSA-2021:4292
Fixedlibecap-debugsource-0:1.0.1-2.module+el8.1.0+4044+36416a77.x86_64 (squid:4) as a component of Red Hat Enterprise Linux AppStream (v. 8)redhat_csaf
For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 After installing this update, the squid service will be restarted automatically.
https://access.redhat.com/errata/RHSA-2021:4292
Fixedlibecap-devel-0:1.0.1-2.module+el8.1.0+4044+36416a77.aarch64 (squid:4) as a component of Red Hat Enterprise Linux AppStream (v. 8)redhat_csaf
For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 After installing this update, the squid service will be restarted automatically.
https://access.redhat.com/errata/RHSA-2021:4292
Fixedlibecap-devel-0:1.0.1-2.module+el8.1.0+4044+36416a77.ppc64le (squid:4) as a component of Red Hat Enterprise Linux AppStream (v. 8)redhat_csaf
For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 After installing this update, the squid service will be restarted automatically.
https://access.redhat.com/errata/RHSA-2021:4292
Fixedlibecap-devel-0:1.0.1-2.module+el8.1.0+4044+36416a77.s390x (squid:4) as a component of Red Hat Enterprise Linux AppStream (v. 8)redhat_csaf
For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 After installing this update, the squid service will be restarted automatically.
https://access.redhat.com/errata/RHSA-2021:4292
Fixedlibecap-devel-0:1.0.1-2.module+el8.1.0+4044+36416a77.x86_64 (squid:4) as a component of Red Hat Enterprise Linux AppStream (v. 8)redhat_csaf
For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 After installing this update, the squid service will be restarted automatically.
https://access.redhat.com/errata/RHSA-2021:4292
Fixedsquid-7:4.15-1.module+el8.5.0+11469+24c223d9.aarch64 (squid:4) as a component of Red Hat Enterprise Linux AppStream (v. 8)redhat_csaf
For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 After installing this update, the squid service will be restarted automatically.
https://access.redhat.com/errata/RHSA-2021:4292
Fixedsquid-7:4.15-1.module+el8.5.0+11469+24c223d9.ppc64le (squid:4) as a component of Red Hat Enterprise Linux AppStream (v. 8)redhat_csaf
For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 After installing this update, the squid service will be restarted automatically.
https://access.redhat.com/errata/RHSA-2021:4292
Fixedsquid-7:4.15-1.module+el8.5.0+11469+24c223d9.s390x (squid:4) as a component of Red Hat Enterprise Linux AppStream (v. 8)redhat_csaf
For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 After installing this update, the squid service will be restarted automatically.
https://access.redhat.com/errata/RHSA-2021:4292
Fixedsquid-7:4.15-1.module+el8.5.0+11469+24c223d9.src (squid:4) as a component of Red Hat Enterprise Linux AppStream (v. 8)redhat_csaf
For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 After installing this update, the squid service will be restarted automatically.
https://access.redhat.com/errata/RHSA-2021:4292
Fixedsquid-7:4.15-1.module+el8.5.0+11469+24c223d9.x86_64 (squid:4) as a component of Red Hat Enterprise Linux AppStream (v. 8)redhat_csaf
For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 After installing this update, the squid service will be restarted automatically.
https://access.redhat.com/errata/RHSA-2021:4292
Fixedsquid-debuginfo-7:4.15-1.module+el8.5.0+11469+24c223d9.aarch64 (squid:4) as a component of Red Hat Enterprise Linux AppStream (v. 8)redhat_csaf
For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 After installing this update, the squid service will be restarted automatically.
https://access.redhat.com/errata/RHSA-2021:4292
Fixedsquid-debuginfo-7:4.15-1.module+el8.5.0+11469+24c223d9.ppc64le (squid:4) as a component of Red Hat Enterprise Linux AppStream (v. 8)redhat_csaf
For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 After installing this update, the squid service will be restarted automatically.
https://access.redhat.com/errata/RHSA-2021:4292
Fixedsquid-debuginfo-7:4.15-1.module+el8.5.0+11469+24c223d9.s390x (squid:4) as a component of Red Hat Enterprise Linux AppStream (v. 8)redhat_csaf
For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 After installing this update, the squid service will be restarted automatically.
https://access.redhat.com/errata/RHSA-2021:4292
Fixedsquid-debuginfo-7:4.15-1.module+el8.5.0+11469+24c223d9.x86_64 (squid:4) as a component of Red Hat Enterprise Linux AppStream (v. 8)redhat_csaf
For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 After installing this update, the squid service will be restarted automatically.
https://access.redhat.com/errata/RHSA-2021:4292
Fixedsquid-debugsource-7:4.15-1.module+el8.5.0+11469+24c223d9.aarch64 (squid:4) as a component of Red Hat Enterprise Linux AppStream (v. 8)redhat_csaf
For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 After installing this update, the squid service will be restarted automatically.
https://access.redhat.com/errata/RHSA-2021:4292
Fixedsquid-debugsource-7:4.15-1.module+el8.5.0+11469+24c223d9.ppc64le (squid:4) as a component of Red Hat Enterprise Linux AppStream (v. 8)redhat_csaf
For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 After installing this update, the squid service will be restarted automatically.
https://access.redhat.com/errata/RHSA-2021:4292
Fixedsquid-debugsource-7:4.15-1.module+el8.5.0+11469+24c223d9.s390x (squid:4) as a component of Red Hat Enterprise Linux AppStream (v. 8)redhat_csaf
For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 After installing this update, the squid service will be restarted automatically.
https://access.redhat.com/errata/RHSA-2021:4292
Fixedsquid-debugsource-7:4.15-1.module+el8.5.0+11469+24c223d9.x86_64 (squid:4) as a component of Red Hat Enterprise Linux AppStream (v. 8)redhat_csaf
For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 After installing this update, the squid service will be restarted automatically.
https://access.redhat.com/errata/RHSA-2021:4292
Workaroundlibecap-0:1.0.1-2.module+el8.1.0+4044+36416a77.aarch64 (squid:4) as a component of Red Hat Enterprise Linux AppStream (v. 8)redhat_csaf
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
Workaroundlibecap-0:1.0.1-2.module+el8.1.0+4044+36416a77.ppc64le (squid:4) as a component of Red Hat Enterprise Linux AppStream (v. 8)redhat_csaf
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
Workaroundlibecap-0:1.0.1-2.module+el8.1.0+4044+36416a77.s390x (squid:4) as a component of Red Hat Enterprise Linux AppStream (v. 8)redhat_csaf
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
Workaroundlibecap-0:1.0.1-2.module+el8.1.0+4044+36416a77.src (squid:4) as a component of Red Hat Enterprise Linux AppStream (v. 8)redhat_csaf
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
Workaroundlibecap-0:1.0.1-2.module+el8.1.0+4044+36416a77.x86_64 (squid:4) as a component of Red Hat Enterprise Linux AppStream (v. 8)redhat_csaf
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
Workaroundlibecap-debuginfo-0:1.0.1-2.module+el8.1.0+4044+36416a77.aarch64 (squid:4) as a component of Red Hat Enterprise Linux AppStream (v. 8)redhat_csaf
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
Workaroundlibecap-debuginfo-0:1.0.1-2.module+el8.1.0+4044+36416a77.ppc64le (squid:4) as a component of Red Hat Enterprise Linux AppStream (v. 8)redhat_csaf
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
Workaroundlibecap-debuginfo-0:1.0.1-2.module+el8.1.0+4044+36416a77.s390x (squid:4) as a component of Red Hat Enterprise Linux AppStream (v. 8)redhat_csaf
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
Workaroundlibecap-debuginfo-0:1.0.1-2.module+el8.1.0+4044+36416a77.x86_64 (squid:4) as a component of Red Hat Enterprise Linux AppStream (v. 8)redhat_csaf
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
Workaroundlibecap-debugsource-0:1.0.1-2.module+el8.1.0+4044+36416a77.aarch64 (squid:4) as a component of Red Hat Enterprise Linux AppStream (v. 8)redhat_csaf
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
Workaroundlibecap-debugsource-0:1.0.1-2.module+el8.1.0+4044+36416a77.ppc64le (squid:4) as a component of Red Hat Enterprise Linux AppStream (v. 8)redhat_csaf
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
Workaroundlibecap-debugsource-0:1.0.1-2.module+el8.1.0+4044+36416a77.s390x (squid:4) as a component of Red Hat Enterprise Linux AppStream (v. 8)redhat_csaf
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
Workaroundlibecap-debugsource-0:1.0.1-2.module+el8.1.0+4044+36416a77.x86_64 (squid:4) as a component of Red Hat Enterprise Linux AppStream (v. 8)redhat_csaf
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
Workaroundlibecap-devel-0:1.0.1-2.module+el8.1.0+4044+36416a77.aarch64 (squid:4) as a component of Red Hat Enterprise Linux AppStream (v. 8)redhat_csaf
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
Workaroundlibecap-devel-0:1.0.1-2.module+el8.1.0+4044+36416a77.ppc64le (squid:4) as a component of Red Hat Enterprise Linux AppStream (v. 8)redhat_csaf
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
Workaroundlibecap-devel-0:1.0.1-2.module+el8.1.0+4044+36416a77.s390x (squid:4) as a component of Red Hat Enterprise Linux AppStream (v. 8)redhat_csaf
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
Workaroundlibecap-devel-0:1.0.1-2.module+el8.1.0+4044+36416a77.x86_64 (squid:4) as a component of Red Hat Enterprise Linux AppStream (v. 8)redhat_csaf
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
Workaroundsquid-7:4.15-1.module+el8.5.0+11469+24c223d9.aarch64 (squid:4) as a component of Red Hat Enterprise Linux AppStream (v. 8)redhat_csaf
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
Workaroundsquid-7:4.15-1.module+el8.5.0+11469+24c223d9.ppc64le (squid:4) as a component of Red Hat Enterprise Linux AppStream (v. 8)redhat_csaf
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
Workaroundsquid-7:4.15-1.module+el8.5.0+11469+24c223d9.s390x (squid:4) as a component of Red Hat Enterprise Linux AppStream (v. 8)redhat_csaf
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
Workaroundsquid-7:4.15-1.module+el8.5.0+11469+24c223d9.src (squid:4) as a component of Red Hat Enterprise Linux AppStream (v. 8)redhat_csaf
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
Workaroundsquid-7:4.15-1.module+el8.5.0+11469+24c223d9.x86_64 (squid:4) as a component of Red Hat Enterprise Linux AppStream (v. 8)redhat_csaf
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
Workaroundsquid-debuginfo-7:4.15-1.module+el8.5.0+11469+24c223d9.aarch64 (squid:4) as a component of Red Hat Enterprise Linux AppStream (v. 8)redhat_csaf
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
Workaroundsquid-debuginfo-7:4.15-1.module+el8.5.0+11469+24c223d9.ppc64le (squid:4) as a component of Red Hat Enterprise Linux AppStream (v. 8)redhat_csaf
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
Workaroundsquid-debuginfo-7:4.15-1.module+el8.5.0+11469+24c223d9.s390x (squid:4) as a component of Red Hat Enterprise Linux AppStream (v. 8)redhat_csaf
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
Workaroundsquid-debuginfo-7:4.15-1.module+el8.5.0+11469+24c223d9.x86_64 (squid:4) as a component of Red Hat Enterprise Linux AppStream (v. 8)redhat_csaf
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
Workaroundsquid-debugsource-7:4.15-1.module+el8.5.0+11469+24c223d9.aarch64 (squid:4) as a component of Red Hat Enterprise Linux AppStream (v. 8)redhat_csaf
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
Workaroundsquid-debugsource-7:4.15-1.module+el8.5.0+11469+24c223d9.ppc64le (squid:4) as a component of Red Hat Enterprise Linux AppStream (v. 8)redhat_csaf
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
Workaroundsquid-debugsource-7:4.15-1.module+el8.5.0+11469+24c223d9.s390x (squid:4) as a component of Red Hat Enterprise Linux AppStream (v. 8)redhat_csaf
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
Workaroundsquid-debugsource-7:4.15-1.module+el8.5.0+11469+24c223d9.x86_64 (squid:4) as a component of Red Hat Enterprise Linux AppStream (v. 8)redhat_csaf
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.

cvss

Technical severity, 0–10. One row per scoring source.

6.5

010

base score 0–10 · higher = more severe · hover a vector to decode

v2.04mediumAV:N/AC:L/Au:S/C:N/I:N/A:Pprimary · NVD / NIST USexploitability 8 · impact 2.9

v3.16.5mediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:Hprimary · NVD / NIST USexploitability 2.8 · impact 3.6

v3.16.5mediumAV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:Hsecondary · FSTEC (BDU) RU

v3.16.5mediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:Hsecondary · OSV

v3.16.5mediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H/E:Hsecondary · CVSS-BT (t0sche)

v3.16.5mediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:Hsecondary · Red Hat Product Security US

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-116USprimaryCWE-20USCWE-20US

exploits (1)

Public proof-of-concept and weaponised exploit code.

auxiliary/dos/http/squid_range_dosSquid Proxy Range Header DoSfunctional · metasploit

affected products (62)

Products and version ranges known to be affected.

Amazon Linux 2all versionscert_bundDEcpe:/o:amazon:linux_2:-
Debian Linuxall versionscert_bundDEcpe:/o:debian:debian_linux:-
Gentoo Linuxall versionscert_bundDEcpe:/o:gentoo:linux:-
Open Source Arch Linuxall versionscert_bundDEcpe:/o:archlinux:archlinux:-
Open Source Squid <3.5.28all versionscert_bundDE
Open Source Squid <4.15all versionscert_bundDE
Open Source Squid <=5.0.6all versionscert_bundDE
Oracle Linuxall versionscert_bundDEcpe:/o:oracle:linux:-
Red Hat Enterprise Linuxall versionscert_bundDEcpe:/o:redhat:enterprise_linux:-
SUSE Linuxall versionscert_bundDEcpe:/o:suse:suse_linux:-
Ubuntu Linuxall versionscert_bundDEcpe:/o:canonical:ubuntu_linux:-
Open Source Squid≤ 5.0.6cert_bundDE
Open Source Squid< 3.5.28cert_bundDE
Open Source Squid< 4.15cert_bundDE
n/a n/a≤ n/aenisa_euvdEU
Red Hat Inc. Red Hat Enterprise Linux≤ 8fstec_bduRU
Squid Software Foundation Squid2.0 → 4.15fstec_bduRU
Squid Software Foundation Squid5.0.1 → 5.0.6fstec_bduRU
АО «Концерн ВНИИНС» ОС ОН «Стрелец»≤ 16.01.2023fstec_bduRU
АО «НППКТ» ОСОН ОСнова Оnyx≤ 2.1fstec_bduRU

showing 20 of 62

advisories (4)

Vendor and ecosystem advisories describing this.

RHSA-2021:4292Red Hat Security Advisory: squid:4 security, bug fix, and enhancement update2021-11-09csaf · redhat_csafUS
An update for the squid:4 module is now available for Red Hat Enterprise Linux 8. Red Hat Product Security has rated this update as having a security impact of Moderate. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.
WID-SEC-W-2022-0672Squid: Mehrere Schwachstellen ermöglichen Denial of ServiceDeutsch2021-05-10csaf · cert_bundDE
Ein entfernter, anonymer Angreifer kann mehrere Schwachstellen in Squid ausnutzen, um einen Denial of Service Angriff durchzuführen.
CVE-2021-318072021-06-08vendor · osvUS
An issue was discovered in Squid before 4.15 and 5.x before 5.0.6. An integer overflow problem allows a remote server to achieve Denial of Service when delivering responses to HTTP Range requests. The issue trigger is a header that can be expected to exist in HTTP traffic without any malicious intent.
CVE-2021-318082021-05-27vendor · osvUS
An issue was discovered in Squid before 4.15 and 5.x before 5.0.6. Due to an input-validation bug, it is vulnerable to a Denial of Service attack (against all clients using the proxy). A client sends an HTTP Range request to trigger this.

also known as (5)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd fstec_bdu osv cert_bund redhat_csaf NVD CVE.org MITRE

published 2021-05-27modified 2026-06-17

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references (40)

External citations — patches, advisories, analysis.

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