Cyber Resilience

CVE-2021-22959

MediumPublic PoC

Published: 15 November 2021

Published
15 November 2021
Modified
21 November 2024
KEV Added
—
Patch
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CVSS Score v3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
EPSS Score 0.0016 37.1th percentile
Risk Priority 13 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-22959 is a medium-severity HTTP Request/Response Smuggling (CWE-444) vulnerability in Llhttp Llhttp. Its CVSS base score is 6.5 (Medium).

Operationally, ranked at the 37.1th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

EU & UK References

Vulnerability details

The parser in accepts requests with a space (SP) right after the header name before the colon. This can lead to HTTP Request Smuggling (HRS) in llhttp < v2.1.4 and < v6.0.6.

CWE(s)
CWE-444

Related Threats

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

Affected Assets

llhttp
llhttp
≤ 2.1.4 · 3.0.0 — 6.0.6
oracle
graalvm
20.3.4, 21.3.0
debian
debian linux
11.0

Mitigating Controls

No mitigating controls mapped yet. The per-CVE control annotator has not reached this CVE.

References