When folding a long comment in an email header containing exclusively unfoldable characters, the parenthesis would not be preserved. This could be used for injecting headers into email messages where addresses are user-controlled and not sanitized.
Weakness
The product uses CRLF (carriage return line feeds) as a special element, e.g. to separate lines or records, but it does not neutralize or incorrectly neutralizes CRLF sequences from inputs.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Python3.10 | Ubuntu | jammy | * |
| Python3.11 | Ubuntu | esm-apps/jammy | * |
| Python3.11 | Ubuntu | jammy | * |
| Python3.12 | Ubuntu | noble | * |
| Python3.13 | Ubuntu | questing | * |
| Python3.14 | Ubuntu | questing | * |
| Python3.6 | Ubuntu | esm-infra/bionic | * |
| Python3.7 | Ubuntu | esm-apps/bionic | * |
| Python3.8 | Ubuntu | esm-apps/bionic | * |
| Python3.8 | Ubuntu | esm-infra/focal | * |
| Python3.9 | Ubuntu | esm-apps/focal | * |
Potential Mitigations
Related Attack Patterns
References
- https://github.com/python/cpython/commit/003b8315669b9f08b1010a49071f73f15f818094
- https://github.com/python/cpython/commit/17d1490aa97bd6b98a42b1a9b324ead84e7fd8a2
- https://github.com/python/cpython/commit/61614a5e5056e4f61ced65008d4576f3df34acb6
- https://github.com/python/cpython/commit/a76e4cd62dd68e7cbe86e37e6ed988495a646b66
- https://github.com/python/cpython/commit/e9970f077240c7c670e8a6fc6662f2b30d3b6ad0
- https://github.com/python/cpython/commit/f738386838021c762efea6c9802c82de65e87796
- https://github.com/python/cpython/issues/143935
- https://github.com/python/cpython/pull/143936
- https://mail.python.org/archives/list/security-announce@python.org/thread/FELSEOLBI2QR6YLG6Q7VYF7FWSGQTKLI/