Cyber Resilience

CVE-2025-12205

Memory Safety in Kamailio 5.5.0

Public PoCMemory Safety
Published
27 October 2025
Modified
29 April 2026
CVSS Score v4 1.9
Click a component to see what it means
Raw vectorCVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS Score 0.0021 11th percentile
Risk Priority 15 floored blend · peak EPSS

Summary

CVE-2025-12205 is a low-severity Improper Restriction of Operations within the Bounds of a Memory Buffer (CWE-119) vulnerability in Kamailio Kamailio. Its CVSS base score is 1.9 (Low).

Operationally, exploitation aligns with the MITRE ATT&CK technique Application or System Exploitation (T1499.004); ranked at the 11th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

The strongest mitigations our analysis identified map to AC-6 (Least Privilege) and CM-5 (Access Restrictions for Change) — see the control section below for these in your framework.

EU & UK References

Vulnerability Data

A vulnerability was detected in Kamailio 5.5. The affected element is the function sr_push_yy_state of the file src/core/cfg.lex of the component Configuration File Handler. The manipulation results in use after free. The attack must be initiated from a local position.…

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The exploit is now public and may be used. The real existence of this vulnerability is still doubted at the moment. This attack requires manipulating config files which might not be a realistic scenario in many cases. The vendor was contacted early about this disclosure but did not respond in any way.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1499.004 Application or System Exploitation Impact
Adversaries may exploit software vulnerabilities that can cause an application or system to crash and deny availability to users.
Why these techniques?

Use-after-free vulnerability in Kamailio configuration file parser enables local exploitation to crash the SIP server process, facilitating endpoint denial of service via application or system exploitation.

CVEs Like This One

CVE-2026-39863Same product: Kamailio Kamailio
CVE-2025-12204Same product: Kamailio Kamailio
CVE-2026-2660Shared CWE-119, CWE-416
CVE-2026-43810Shared CWE-119, CWE-416
CVE-2024-30808Shared CWE-416
CVE-2024-52923Shared CWE-119
CVE-2024-25385Shared CWE-416
CVE-2024-36129Shared CWE-119
CVE-2024-30807Shared CWE-416
CVE-2023-6039Shared CWE-416

Affected Assets

kamailio
kamailio
5.5.0

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)
  • CM-5 Access Restrictions for Change
  • AC-6 Least Privilege
  • AC-3 Access Enforcement
Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)
  • 3 hardening rules · 3 OS baselines
Validate
Prove the fix (OWASP ASVS)
  • V17.3.2
  • V1.4.3

Mitigating Controls (NIST 800-53 r5) AI

prevent

Directly restricts who may modify Kamailio configuration files, blocking the local manipulation required to trigger the use-after-free in sr_push_yy_state.

prevent

Enforces least-privilege file permissions so that only authorized accounts can write to cfg.lex-parsed configuration files.

prevent

Enforces access-control policy on the Configuration File Handler, limiting the subjects permitted to supply crafted configuration input.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure SDLC practices (bounds checking, safe APIs, reviews) directly prevent this class of flaw.

ID.RA-01 partial match
prevents

Vulnerability scanning and code analysis directly surface buffer-boundary flaws.

ID.RA-08 partial match
prevents

Receiving and triaging vulnerability disclosures commonly includes buffer-related reports.

PR.AT-02 partial match
prevents

Developer training on secure coding reduces introduction of memory-buffer errors.

PR.PS-02 partial match
prevents

Patching replaces vulnerable code containing buffer-boundary defects.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

detects

Security testing in development catches out-of-bounds accesses before release, covering most instances of the weakness.

prevents

Secure development lifecycle mandates memory-safety practices that directly prevent buffer-boundary violations.

prevents

Application security requirements can specify memory-safety rules, but do not prescribe implementation details.

prevents

Secure architecture and engineering principles include memory-safe design patterns that mitigate buffer overflows.

prevents

Secure coding standards explicitly forbid unsafe buffer operations, directly eliminating CWE-119.

prevents

Change-management processes help ensure memory-safety fixes are deployed consistently.

References