CVE-2001-0851

mediumpriority · track · 21EPSS 0.030 · 87 %ileEURUUS
grimoire priorityP3 · Track
Exploitable?
—
no known exploitation
Likely / severe?
3.00% (87th) EPSS
CVSS 5 · medium
Is it mine?
21 products
Check your exposure
Who says so?
4 sources
enisa_euvd · fstec_bdu · nvd · redhat_csaf

EPSS · scored 2026-10-27

Linux kernel 2.0, 2.2 and 2.4 with syncookies enabled allows remote attackers to bypass firewall rules by brute force guessing the cookie.

01

remediations

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

A vendor fix is available.

  • FixedRed Hat Linux 6.2redhat_csaf

    Before applying this update, make sure all previously released errata relevant to your system have been applied. The procedure for upgrading the kernel is documented at: http://www.redhat.com/support/docs/howto/kernel-upgrade/ Please read the directions for your architecture carefully before proceeding with the kernel upgrade. Please note that this update is also available via Red Hat Network. Many people find this to be an easier way to apply updates. To use Red Hat Network, launch the Red Hat Update Agent with the following command: up2date This will start an interactive process that will result in the appropriate RPMs being upgraded on your system. Note that you need to select the kernel explicitly on default configurations of up2date.

    https://access.redhat.com/errata/RHSA-2001:142
  • FixedRed Hat Linux 7.0redhat_csaf

    Before applying this update, make sure all previously released errata relevant to your system have been applied. The procedure for upgrading the kernel is documented at: http://www.redhat.com/support/docs/howto/kernel-upgrade/ Please read the directions for your architecture carefully before proceeding with the kernel upgrade. Please note that this update is also available via Red Hat Network. Many people find this to be an easier way to apply updates. To use Red Hat Network, launch the Red Hat Update Agent with the following command: up2date This will start an interactive process that will result in the appropriate RPMs being upgraded on your system. Note that you need to select the kernel explicitly on default configurations of up2date.

    https://access.redhat.com/errata/RHSA-2001:142
  • FixedRed Hat Linux 7.1redhat_csaf

    Before applying this update, make sure all previously released errata relevant to your system have been applied. The procedure for upgrading the kernel is documented at: http://www.redhat.com/support/docs/howto/kernel-upgrade/ Please read the directions for your architecture carefully before proceeding with the kernel upgrade. Please note that this update is also available via Red Hat Network. Many people find this to be an easier way to apply updates. To use Red Hat Network, launch the Red Hat Update Agent with the following command: up2date This will start an interactive process that will result in the appropriate RPMs being upgraded on your system. Note that you need to select the kernel explicitly on default configurations of up2date.

    https://access.redhat.com/errata/RHSA-2001:142
  • FixedRed Hat Linux 7.2redhat_csaf

    Before applying this update, make sure all previously released errata relevant to your system have been applied. The procedure for upgrading the kernel is documented at: http://www.redhat.com/support/docs/howto/kernel-upgrade/ Please read the directions for your architecture carefully before proceeding with the kernel upgrade. Please note that this update is also available via Red Hat Network. Many people find this to be an easier way to apply updates. To use Red Hat Network, launch the Red Hat Update Agent with the following command: up2date This will start an interactive process that will result in the appropriate RPMs being upgraded on your system. Note that you need to select the kernel explicitly on default configurations of up2date.

    https://access.redhat.com/errata/RHSA-2001:142
02

cvss

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

7.5
010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 4.3–7.5

v2.05mediumAV:N/AC:L/Au:N/C:P/I:N/A:Nprimary · NVD / NIST USexploitability 10 · impact 2.9
v2.07.5highAV:N/AC:L/Au:N/C:P/I:P/A:Psecondary · FSTEC (BDU) RU
v2.04.3mediumAV:N/AC:L/Au:N/C:P/I:N/A:N/E:Usecondary · CVSS-BT (t0sche)
03

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-284USLLM-inferredCWE-307USLLM-inferred
04

affected products (21)

Products and version ranges known to be affected.

showing 20 of 21
05

advisories (1)

Vendor and ecosystem advisories describing this.

  • RHSA-2001:142Red Hat Security Advisory: kernel 2.2 and 2.42001-11-02csaf · redhat_csafUS

    Syncookies are used to protect a system against certain Denial Of Service (DOS) attacks. A flaw in this mechanism has been found which can be used to circumvent certain types of firewall configurations. Note: syncookies are not enabled in the default installation of Red Hat Linux but many server administrators do enable syncookies.

06

also known as (14)

Other names and identifiers for this entity.

07

sources

Which sources assert this record, and when.

enisa_euvdfstec_bdunvdredhat_csafNVDCVE.orgMITRE
published 2001-12-06modified 2026-06-16
08

references (14)

External citations — patches, advisories, analysis.

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