Cyber Resilience

CVE-2021-38751

MediumPublic PoC

Published: 16 August 2021

Published
16 August 2021
Modified
21 November 2024
KEV Added
Patch
CVSS Score v3.1 4.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N
EPSS Score 0.0831 92.5th percentile
Risk Priority 14 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-38751 is a medium-severity Improper Encoding or Escaping of Output (CWE-116) vulnerability in Exponentcms Exponentcms. Its CVSS base score is 4.3 (Medium).

Operationally, ranked in the top 7.5% 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

A HTTP Host header attack exists in ExponentCMS 2.6 and below in /exponent_constants.php. A modified HTTP header can change links on the webpage to an arbitrary value, leading to a possible attack vector for MITM.

CWE(s)

Related Threats

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

Affected Assets

exponentcms
exponentcms
≤ 2.6

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-116

Validating that output matches expected content directly mitigates failures to properly encode or escape data for its destination context.

References