| Name | CVE-2021-3733 |
| Description | There's a flaw in urllib's AbstractBasicAuthHandler class. An attacker who controls a malicious HTTP server that an HTTP client (such as web browser) connects to, could trigger a Regular Expression Denial of Service (ReDOS) during an authentication request with a specially crafted payload that is sent by the server to the client. The greatest threat that this flaw poses is to application availability. |
| Source | CVE (at NVD; CERT, LWN, oss-sec, fulldisc, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more) |
| References | DLA-2808-1, DLA-3432-1, DLA-3477-1 |
The table below lists information on source packages.
| Source Package | Release | Version | Status |
|---|---|---|---|
| python2.7 (PTS) | buster | 2.7.16-2+deb10u1 | vulnerable |
| buster (security) | 2.7.16-2+deb10u4 | fixed | |
| bullseye | 2.7.18-8+deb11u1 | vulnerable | |
| python3.7 (PTS) | buster | 3.7.3-2+deb10u3 | vulnerable |
| buster (security) | 3.7.3-2+deb10u7 | fixed | |
| python3.9 (PTS) | bullseye | 3.9.2-1 | vulnerable |
The information below is based on the following data on fixed versions.
| Package | Type | Release | Fixed Version | Urgency | Origin | Debian Bugs |
|---|---|---|---|---|---|---|
| python2.7 | source | buster | 2.7.16-2+deb10u2 | DLA-3432-1 | ||
| python2.7 | source | (unstable) | (unfixed) | |||
| python3.5 | source | stretch | 3.5.3-1+deb9u5 | DLA-2808-1 | ||
| python3.5 | source | (unstable) | (unfixed) | |||
| python3.7 | source | buster | 3.7.3-2+deb10u5 | DLA-3477-1 | ||
| python3.7 | source | (unstable) | (unfixed) | |||
| python3.9 | source | (unstable) | 3.9.7-1 |
[bullseye] - python3.9 <no-dsa> (Minor issue)
[bullseye] - python2.7 <ignored> (Unsupported in Bullseye, only included to build a few applications)
https://bugs.python.org/issue43075
https://github.com/python/cpython/pull/24391
https://github.com/python/cpython/commit/7215d1ae25525c92b026166f9d5cac85fb1defe1 (master)
https://github.com/python/cpython/commit/a21d4fbd549ec9685068a113660553d7f80d9b09 (3.9.5)
https://github.com/python/cpython/commit/e7654b6046090914a8323931ed759a94a5f85d60 (3.8.10)
https://github.com/python/cpython/commit/ada14995870abddc277addf57dd690a2af04c2da (3.7.11)
https://github.com/python/cpython/commit/3fbe96123aeb66664fa547a8f6022efa2dc8788f (3.6.14)