Cyber Resilience

CVE-2021-23336

MediumPublic PoC

Published: 15 February 2021

Published
15 February 2021
Modified
17 December 2025
KEV Added
Patch
19 February 2021
CVSS Score v3.1 5.9 CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:L/A:H
EPSS Score 0.0031 54.7th percentile
Risk Priority 12 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-23336 is a medium-severity HTTP Request/Response Smuggling (CWE-444) vulnerability in Python Python. Its CVSS base score is 5.9 (Medium).

Operationally, ranked in the top 45.3% 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

The package python/cpython from 0 and before 3.6.13, from 3.7.0 and before 3.7.10, from 3.8.0 and before 3.8.8, from 3.9.0 and before 3.9.2 are vulnerable to Web Cache Poisoning via urllib.parse.parse_qsl and urllib.parse.parse_qs by using a vector called parameter cloaking.…

more

When the attacker can separate query parameters using a semicolon (;), they can cause a difference in the interpretation of the request between the proxy (running with default configuration) and the server. This can result in malicious requests being cached as completely safe ones, as the proxy would usually not see the semicolon as a separator, and therefore would not include it in a cache key of an unkeyed parameter.

CWE(s)

Related Threats

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

Affected Assets

python
python
≤ 3.6.13 · 3.7.0 — 3.7.10 · 3.8.0 — 3.8.8
fedoraproject
fedora
32, 33, 34
debian
debian linux
9.0
netapp
cloud backup
all versions
netapp
inventory collect tool
all versions
netapp
ontap select deploy administration utility
all versions
netapp
snapcenter
all versions
djangoproject
django
2.2 — 2.2.19 · 3.0 — 3.0.13 · 3.1 — 3.1.7
oracle
communications offline mediation controller
12.0.0.3.0
oracle
communications pricing design center
12.0.0.3.0
+2 more product configuration(s) — see NVD for full list

Mitigating Controls

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

References