Public on 2023-08-25
Modified on 2024-01-12
An issue was discovered in Python before 3.8.18, 3.9.x before 3.9.18, 3.10.x before 3.10.13, and 3.11.x before 3.11.5. It primarily affects servers (such as HTTP servers) that use TLS client authentication. If a TLS server-side socket is created, receives data into the socket buffer, and then is closed quickly, there is a brief window where the SSLSocket instance will detect the socket as "not connected" and won't initiate a handshake, but buffered data will still be readable from the socket buffer. This data will not be authenticated if the server-side TLS peer is expecting client certificate authentication, and is indistinguishable from valid TLS stream data. Data is limited in size to the amount that will fit in the buffer. (The TLS connection cannot directly be used for data exfiltration because the vulnerable code path requires that the connection be closed on initialization of the SSLSocket.)
Medium severity
CVSS v3 Base Score
See breakdown

Affected Packages

Platform Package Release Date Advisory Status
Amazon Linux 2 - Core python Pending Fix
Amazon Linux 1 python27 2023-10-30 ALAS-2023-1876 Fixed
Amazon Linux 2 - Core python3 2023-08-31 ALAS2-2023-2222 Fixed
Amazon Linux 2023 python3.11 2023-08-31 ALAS2023-2023-317 Fixed
Amazon Linux 2023 python3.9 2023-08-31 ALAS2023-2023-319 Fixed
Amazon Linux 1 python38 2023-08-30 ALAS-2023-1816 Fixed
Amazon Linux 2 - Python3.8 Extra python38 2023-09-06 ALAS2PYTHON3.8-2023-010 Fixed

CVSS Scores

Score Type Score Vector
Amazon Linux CVSSv3 5.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N