Cyber Resilience

CVE-2021-28040

HighPublic PoCDDoS

Published: 05 March 2021

Published
05 March 2021
Modified
21 November 2024
KEV Added
Patch
CVSS Score v3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS Score 0.0028 51.7th percentile
Risk Priority 15 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-28040 is a high-severity Uncontrolled Recursion (CWE-674) vulnerability in Ossec Ossec. Its CVSS base score is 7.5 (High).

Operationally, ranked in the top 48.3% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

EU & UK References

Vulnerability details

An issue was discovered in OSSEC 3.6.0. An uncontrolled recursion vulnerability in os_xml.c occurs when a large number of opening and closing XML tags is used. Because recursion is used in _ReadElem without restriction, an attacker can trigger a segmentation…

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fault once unmapped memory is reached.

CWE(s)

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

ossec
ossec
3.6.0

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