Cyber Resilience

CVE-2021-42756

Critical

Published: 16 February 2023

Published
16 February 2023
Modified
21 November 2024
KEV Added
Patch
CVSS Score v3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.6646 98.6th percentile
Risk Priority 59 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-42756 is a critical-severity Stack-based Buffer Overflow (CWE-121) vulnerability in Fortinet Fortiweb. Its CVSS base score is 9.8 (Critical).

Operationally, ranked in the top 1.4% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

Multiple stack-based buffer overflow vulnerabilities [CWE-121] in the proxy daemon of FortiWeb 5.x all versions, 6.0.7 and below, 6.1.2 and below, 6.2.6 and below, 6.3.16 and below, 6.4 all versions may allow an unauthenticated remote attacker to achieve arbitrary code…

more

execution via specifically crafted HTTP requests.

CWE(s)

Related Threats

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

Affected Assets

fortinet
fortiweb
5.6.0 — 6.0.8 · 6.1.0 — 6.1.3 · 6.2.0 — 6.2.7

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-787

Out-of-bounds writes that corrupt control flow or inject shellcode are rendered non-executable by the same memory protections.

References