Public bug reported: -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA512
affects ubuntu/cron An administrator-created /etc/cron.deny file fails to deny its final username when that line has no terminating newline. For example, if the file consists of the bytes "blocked" with no LF, the user blocked can still run crontab(1), assuming cron.allow is absent. The administrator expects that username to be denied. Ubuntu does not create cron.deny by default; this requires an administrator to use it and leave the final line unterminated. It is a conditional policy/correctness bug, not evidence of privilege escalation. Debian report with an issue-specific patch and regression test: https://bugs.debian.org/1152898 The fix reads complete physical records, matches an unterminated final line, accepts CRLF, and skips overlong or NUL-containing records without consuming the next valid entry. The patched Ubuntu source passed focused tests in a disposable container, and the Debian patch passed the existing Debian integration suite. Ubuntu and Debian Security Teams recommended public bug reports. Please consider the fix for Ubuntu and supported-release backports as appropriate. Brett Sutton -----BEGIN PGP SIGNATURE----- iHUEARYKAB0WIQT9urELYHGjhO/7gF+TZqY73ysXxAUCauk/EQAKCRCTZqY73ysX xA2sAQCOqV6xWNIK9M/h7JgK4CtM5wQ4GvZLngIFafL0qgMckwD+KHsgh9jH1myW 8hoF2XTeKTVTpRo+jG2axGNfcqO+wgU= =EgOs -----END PGP SIGNATURE----- ** Affects: cron (Ubuntu) Importance: Undecided Status: New -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2172793 Title: cron.deny ignores its final user when the file has no trailing newline To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/cron/+bug/2172793/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
