View at Official debian advisory, NVD, CVE.org · CVE detail
Freshness: upstream tracker timestamp is available; use API updated time as primary recency signal.
CVE-2021-3733 not yet assigned priority: Debian including 3 source packages (pypy3, python2.7, python3.9), 7 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 6, open 1.
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.