{"id":"UBUNTU-CVE-2021-3737","details":"A flaw was found in python. An improperly handled HTTP response in the HTTP client code of python may allow a remote attacker, who controls the HTTP server, to make the client script enter an infinite loop, consuming CPU time. The highest threat from this vulnerability is to system availability.","modified":"2026-04-22T14:52:36.827468Z","published":"2021-08-31T00:00:00Z","related":["USN-5083-1","USN-5199-1","USN-5200-1","USN-5201-1","USN-6891-1"],"upstream":["CVE-2021-3737"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2021-3737"},{"type":"REPORT","url":"https://bugs.python.org/issue44022"},{"type":"REPORT","url":"https://github.com/python/cpython/pull/25916"},{"type":"REPORT","url":"https://github.com/python/cpython/pull/26503"},{"type":"REPORT","url":"https://github.com/python/cpython/commit/60ba0b68470a584103e28958d91e93a6db37ec92"},{"type":"REPORT","url":"https://github.com/python/cpython/commit/ea9327036680acc92d9f89eaf6f6a54d2f8d78d9"},{"type":"REPORT","url":"https://github.com/python/cpython/commit/f396864ddfe914531b5856d7bf852808ebfc01ae"},{"type":"REPORT","url":"https://github.com/python/cpython/commit/078b146f062d212919d0ba25e34e658a8234aa63"},{"type":"REPORT","url":"https://github.com/python/cpython/commit/f68d2d69f1da56c2aea1293ecf93ab69a6010ad7"},{"type":"REPORT","url":"https://github.com/python/cpython/commit/98e5a7975d99b58d511f171816ecdfb13d5cca18"},{"type":"REPORT","url":"https://github.com/python/cpython/commit/5df4abd6b033a5f1e48945c6988b45e35e76f647"},{"type":"REPORT","url":"https://github.com/python/cpython/commit/0389426fa4af4dfc8b1d7f3f291932d928392d8b"},{"type":"REPORT","url":"https://github.com/python/cpython/commit/fee96422e6f0056561cf74fef2012cc066c9db86"},{"type":"REPORT","url":"https://github.com/python/cpython/commit/1b6f4e5e13ebd1f957b47f7415b53d0869bdbac6"},{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-5083-1"},{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-5199-1"},{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-5200-1"},{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-5201-1"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2021-3737"},{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-6891-1"}],"affected":[{"package":{"name":"python3.4","ecosystem":"Ubuntu:Pro:14.04:LTS","purl":"pkg:deb/ubuntu/python3.4@3.4.3-1ubuntu1~14.04.7+esm11?arch=source&distro=trusty/esm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.4.3-1ubuntu1~14.04.7+esm11"}]}],"versions":["3.4~b1-0ubuntu3","3.4~b1-4ubuntu4","3.4~b1-4ubuntu6","3.4~b1-5ubuntu2","3.4~b2-1","3.4~b3-1ubuntu1","3.4~rc1-1build1","3.4~rc2-1","3.4~rc3-0ubuntu1","3.4.0-1","3.4.0-2ubuntu1","3.4.0-2ubuntu1.1","3.4.3-1ubuntu1~14.04.1","3.4.3-1ubuntu1~14.04.3","3.4.3-1ubuntu1~14.04.4","3.4.3-1ubuntu1~14.04.5","3.4.3-1ubuntu1~14.04.6","3.4.3-1ubuntu1~14.04.7","3.4.3-1ubuntu1~14.04.7+esm2","3.4.3-1ubuntu1~14.04.7+esm4","3.4.3-1ubuntu1~14.04.7+esm6","3.4.3-1ubuntu1~14.04.7+esm7","3.4.3-1ubuntu1~14.04.7+esm8","3.4.3-1ubuntu1~14.04.7+esm10"],"ecosystem_specific":{"binaries":[{"binary_version":"3.4.3-1ubuntu1~14.04.7+esm11","binary_name":"idle-python3.4"},{"binary_version":"3.4.3-1ubuntu1~14.04.7+esm11","binary_name":"libpython3.4"},{"binary_version":"3.4.3-1ubuntu1~14.04.7+esm11","binary_name":"libpython3.4-minimal"},{"binary_version":"3.4.3-1ubuntu1~14.04.7+esm11","binary_name":"libpython3.4-stdlib"},{"binary_version":"3.4.3-1ubuntu1~14.04.7+esm11","binary_name":"libpython3.4-testsuite"},{"binary_version":"3.4.3-1ubuntu1~14.04.7+esm11","binary_name":"python3.4"},{"binary_version":"3.4.3-1ubuntu1~14.04.7+esm11","binary_name":"python3.4-examples"},{"binary_version":"3.4.3-1ubuntu1~14.04.7+esm11","binary_name":"python3.4-minimal"},{"binary_version":"3.4.3-1ubuntu1~14.04.7+esm11","binary_name":"python3.4-venv"}],"availability":"Available 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