Cyber Resilience

CVE-2023-50269

HighDDoS

Published: 14 December 2023

Published
14 December 2023
Modified
21 November 2024
KEV Added
Patch
CVSS Score v3.1 8.6 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
EPSS Score 0.0115 78.9th percentile
Risk Priority 18 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2023-50269 is a high-severity Uncontrolled Recursion (CWE-674) vulnerability in Squid-Cache Squid. Its CVSS base score is 8.6 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Application or System Exploitation (T1499.004); ranked in the top 21.1% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

Squid is a caching proxy for the Web. Due to an Uncontrolled Recursion bug in versions 2.6 through 2.7.STABLE9, versions 3.1 through 5.9, and versions 6.0.1 through 6.5, Squid may be vulnerable to a Denial of Service attack against HTTP…

more

Request parsing. This problem allows a remote client to perform Denial of Service attack by sending a large X-Forwarded-For header when the follow_x_forwarded_for feature is configured. This bug is fixed by Squid version 6.6. In addition, patches addressing this problem for the stable releases can be found in Squid's patch archives.

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?

The uncontrolled recursion vulnerability in Squid's HTTP request parsing allows remote unauthenticated attackers to trigger denial of service by sending a large X-Forwarded-For header, enabling endpoint DoS through application exploitation.

MITRE ATLAS TechniquesAI

MITRE ATLAS techniques

AML.T0048: External Harms

Affected Assets

squid-cache
squid
2.6, 2.7 · 3.1 — 5.9 · 6.0.1 — 6.5

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-674

Supports resumption at alternate site when uncontrolled recursion causes primary site failure or crash.

addresses: CWE-674

Prevents uncontrolled recursion that exhausts stack or CPU resources.

References