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.
01
describes (1)
Related CVEs.
| ID | severity | exploitable | ||
|---|---|---|---|---|
| CVE-2021-3733US | medium6.5 | — | ||
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 R… | ||||
02
references
External citations — patches, advisories, analysis.
- https://bugs.python.org/issue43075ADVISORY
- https://bugzilla.redhat.com/show_bug.cgi?id=1995234ADVISORY
- https://github.com/python/cpython/commit/7215d1ae25525c92b026166f9d5cac85fbADVISORY
- https://github.com/python/cpython/pull/24391ADVISORY
- https://lists.debian.org/debian-lts-announce/2023/05/msg00024.htmlWEB
- https://lists.debian.org/debian-lts-announce/2023/06/msg00039.htmlWEB
- https://lists.debian.org/debian-lts-announce/2024/12/msg00000.htmlWEB
- https://nvd.nist.gov/vuln/detail/CVE-2021-3733WEB
scry
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