CVE-2021-23336

NameCVE-2021-23336
DescriptionThe 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. 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.
SourceCVE (at NVD; CERT, LWN, oss-sec, fulldisc, bugtraq, EDB, Metasploit, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, Mageia, GitHub code/issues, web search, more)
ReferencesDLA-2569-1, DLA-2619-1, DLA-2628-1
NVD severitymedium
Debian Bugs983090

Vulnerable and fixed packages

The table below lists information on source packages.

Source PackageReleaseVersionStatus
pypy3 (PTS)buster7.0.0+dfsg-3vulnerable
bullseye, sid7.3.3+dfsg-4fixed
python-django (PTS)stretch1:1.10.7-2+deb9u9vulnerable
stretch (security)1:1.10.7-2+deb9u13fixed
buster, buster (security)1:1.11.29-1~deb10u1vulnerable
bullseye2:2.2.22-1fixed
sid2:2.2.23-1fixed
python2.7 (PTS)stretch2.7.13-2+deb9u3vulnerable
stretch (security)2.7.13-2+deb9u5fixed
buster2.7.16-2+deb10u1vulnerable
bullseye, sid2.7.18-7vulnerable
python3.5 (PTS)stretch3.5.3-1+deb9u1vulnerable
stretch (security)3.5.3-1+deb9u4fixed
python3.7 (PTS)buster3.7.3-2+deb10u3vulnerable
python3.9 (PTS)bullseye, sid3.9.2-1fixed

The information below is based on the following data on fixed versions.

PackageTypeReleaseFixed VersionUrgencyOriginDebian Bugs
pypy3source(unstable)7.3.3+dfsg-3
python-djangosourcestretch1:1.10.7-2+deb9u11DLA-2569-1
python-djangosource(unstable)2:2.2.19-1983090
python2.7sourcestretch2.7.13-2+deb9u5DLA-2628-1
python2.7source(unstable)(unfixed)
python3.5sourcestretch3.5.3-1+deb9u4DLA-2619-1
python3.5source(unstable)(unfixed)
python3.7source(unstable)(unfixed)
python3.8source(unstable)(unfixed)
python3.9source(unstable)3.9.2-1

Notes

[buster] - python-django <no-dsa> (Minor issue; can be fixed via point release)
[buster] - python3.7 <no-dsa> (Minor issue)
[bullseye] - python2.7 <ignored> (Python 2.7 in Bullseye not covered by security support)
[buster] - python2.7 <no-dsa> (Minor issue)
[buster] - pypy3 <no-dsa> (Minor issue)
https://github.com/python/cpython/pull/24297
https://github.com/python/cpython/commit/fcbe0cb04d35189401c0c880ebfb4311e952d776 (master)
https://github.com/python/cpython/commit/c9f07813ab8e664d8c34413c4fc2d4f86c061a92 (3.9)
https://github.com/python/cpython/commit/d0d4d30882fe3ab9b1badbecf5d15d94326fd13e (3.7)
https://snyk.io/blog/cache-poisoning-in-popular-open-source-packages/

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