CVE-2021-23336
Description
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. 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.
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
No mitigations published for this CVE yet.
The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.
✚ Propose a mitigation on Community → Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here withsource_tier=community-verified.
OS impact
SUSE Affected 1 release
| Version | Status | Fixed in |
|---|---|---|
| — | Affected | — |
Arch Fixed 1 release
| Version | Status | Fixed in |
|---|---|---|
| — | Fixed | 3.9.2-1 |
Debian Fixed 5 releases
| Version | Status | Fixed in |
|---|---|---|
| trixie | Fixed | 7.3.3+dfsg-3 |
| sid | Fixed | 7.3.3+dfsg-3 |
| forky | Fixed | 7.3.3+dfsg-3 |
| bullseye | Fixed | 7.3.3+dfsg-3 |
| bookworm | Fixed | 7.3.3+dfsg-3 |
Red Hat Fixed 1 release
| Version | Status | Fixed in |
|---|---|---|
| 8 | Fixed | — |
Rocky Linux Fixed 1 release
| Version | Status | Fixed in |
|---|---|---|
| 8 | Fixed | — |
References
- https://security.archlinux.org/ASA-202102-37
- https://security.archlinux.org/ASA-202102-28
- https://www.suse.com/security/cve/CVE-2021-23336.html
- https://errata.rockylinux.org/RLSA-2021:4162
- https://errata.rockylinux.org/RLSA-2021:4151
- https://security-tracker.debian.org/tracker/CVE-2021-23336
- https://errata.almalinux.org/8/ALSA-2021-4162.html
- https://errata.almalinux.org/8/ALSA-2021-4151.html
- https://access.redhat.com/errata/RHSA-2021:1633
- https://access.redhat.com/errata/RHSA-2021:4151
- https://access.redhat.com/errata/RHSA-2021:4162
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.