CVE-2021-25217

lowpriority · track · 15EPSS 0.061 · 93 %ileDEEURUUS
grimoire priorityP3 · Track
Exploitable?
—
no known exploitation
Likely / severe?
6.12% (93rd) EPSS
CVSS 3.3 · low
Is it mine?
54 products
Check your exposure
Who says so?
7 sources
cnnvd · enisa_euvd · fstec_bdu · cert_bund

EPSS · scored 2026-10-26

In ISC DHCP 4.1-ESV-R1 -> 4.1-ESV-R16, ISC DHCP 4.4.0 -> 4.4.2 (Other branches of ISC DHCP (i.e., releases in the 4.0.x series or lower and releases in the 4.3.x series) are beyond their End-of-Life (EOL) and no longer supported by ISC. From inspection it is clear that the defect is also present in releases from those series, but they have not been officially tested for the vulnerability), The outcome of encountering the defect while reading a lease that will trigger it varies, according to: the component being affected (i.e., dhclient or dhcpd) whether the package was built as a 32-bit or 64-bit binary whether the compiler flag -fstack-protection-strong was used when compiling In dhclient, ISC has not successfully reproduced the error on a 64-bit system. However, on a 32-bit system it is possible to cause dhclient to crash when reading an improper lease, which could cause network connectivity problems for an affected system due to the absence of a running DHCP client process. In dhcpd, when run in DHCPv4 or DHCPv6 mode: if the dhcpd server binary was built for a 32-bit architecture AND the -fstack-protection-strong flag was specified to the compiler, dhcpd may exit while parsing a lease file containing an objectionable lease, resulting in lack of service to clients. Additionally, the offending lease and the lease immediately following it in the lease database may be improperly deleted. if the dhcpd server binary was built for a 64-bit architecture OR if the -fstack-protection-strong compiler flag was NOT specified, the crash will not occur, but it is possible for the offending lease and the lease which immediately followed it to be improperly deleted.

01

remediations

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

A vendor fix is available.

02

cvss

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

8.8
010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · low–high · 2.8–8.8

v2.03.3lowAV:A/AC:L/Au:N/C:N/I:N/A:Pprimary · NVD / NIST USexploitability 6.5 · impact 2.9
v2.02.8lowAV:A/AC:L/Au:N/C:N/I:N/A:P/E:Usecondary · CVSS-BT (t0sche)
v3.18.8highCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:H/E:P/RL:O/RC:Csecondary · CISA US
v3.17.4highAV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:Hsecondary · FSTEC (BDU) RU
v3.17.4highCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:Hsecondary · ENISA EU
v3.17.4highCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:Hsecondary · security-officer@isc.orgexploitability 2.8 · impact 4
v3.18.8highCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:H/E:P/RL:O/RC:Csecondary · Siemens ProductCERT DE
v3.17.4highCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:Hsecondary · SICK PSIRT DE
v3.17.4highCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:Hsecondary · NVD / NIST USexploitability 2.8 · impact 4
03

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-119USprimaryCWE-119USCWE-119USCWE-119USCWE-119US
04

affected products (54)

Products and version ranges known to be affected.

showing 20 of 54
05

advisories (7)

Vendor and ecosystem advisories describing this.

  • SCA-2025-0009Vulnerabilities affecting SICK TDC-E210GC2025-08-01csaf · sick_psirtDE

    SICK has identified multiple vulnerabilities in the SICK TDC-E210GC product. The advisory includes a total of 23 vulnerabilities, of which 14 are confirmed as affected and 9 as known not affected. At this time, SICK is not aware of any public exploits specifically targeting these vulnerabilities. Customers are strongly advised to apply the recommended workaround for the affected vulnerabilities to reduce potential risk.

  • SCA-2025-0011Vulnerabilities affecting Endress+Hauser SSG-E210GC2025-10-02csaf · sick_psirtDE

    Several vulnerabilities in the Endress+Hauser SSG-E210GC product were discoverd. The advisory includes a total of 23 vulnerabilities, of which 14 are confirmed as affected and 9 as known not affected.

  • SSA-406691SSA-406691: Buffer Vulnerabilities in DHCP function of RUGGEDCOM ROX products2022-03-08csaf · siemens_psirtDE

    A vulnerability in the RUGGEDCOM ROX devices' third party component, ISC DHCP, could allow an attacker to cause a buffer overrun due to a bug when reading a stored DHCP lease containing certain option information, eventually leading to a denial-of-service condition, or cause a remote-code execution. Siemens has released updates for the affected products and recommends to update to the latest versions.

  • SSA-637483SSA-637483 Third-Party Component Vulnerabilities in SINEC INS before V1.0 SP22022-09-13csaf · siemens_psirtDE

    Multiple vulnerabilities affecting various third-party components of SINEC INS before V1.0 SP2 could allow an attacker to cause a denial of service condition, disclose sensitive data or violate the system integrity. Siemens has released an update for the SINEC INS and recommends to update to the latest version.

  • WID-SEC-W-2023-0063Juniper Junos Space: Mehrere SchwachstellenDeutsch2022-01-12csaf · cert_bundDE

    Ein Angreifer aus dem angrenzenden Netzwerk oder ein entfernter anonymer, authentisierter oder lokaler Angreifer kann mehrere Schwachstellen in Juniper Junos Space ausnutzen, um Sicherheitsmaßnahmen zu umgehen, vertrauliche Informationen offenzulegen, einen Denial-of-Service-Zustand auszulösen, beliebigen Code auszuführen und seine Privilegien zu erweitern.

  • WID-SEC-W-2023-1261Internet Systems Consortium DHCP: Schwachstelle ermöglicht Denial of ServiceDeutsch2021-05-26csaf · cert_bundDE

    Ein Angreifer aus dem benachbarten Netzwerk kann eine Schwachstelle in Internet Systems Consortium DHCP ausnutzen, um einen Denial of Service Angriff durchzuführen.

  • ICSA-22-258-05Siemens SINEC INS2022-09-13icsa · cisa_csaf_otUS

    Multiple vulnerabilities affecting various third-party components of SINEC INS before V1.0 SP2 could allow an attacker to cause a denial of service condition, disclose sensitive data or violate the system integrity. Siemens has released an update for the SINEC INS and recommends to update to the latest version.

06

also known as (4)

Other names and identifiers for this entity.

07

sources

Which sources assert this record, and when.

cnnvdenisa_euvdfstec_bducert_bundcisa_csaf_otsick_psirtsiemens_psirtNVDCVE.orgMITRE
published 2021-05-26modified 2026-06-17
09

references (59)

External citations — patches, advisories, analysis.

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