Sebastian Krahmer discovered that Postfix, a mail transfer agent, incorrectly checks the ownership of a mailbox. In some configurations, this allows for appending data to arbitrary files as root. Note that only specific configurations are vulnerable; the default Debian installation is not affected. Only a configuration meeting the following requirements is vulnerable: The mail delivery style is mailbox, with the Postfix built-in local(8) or virtual(8) delivery agents. The mail spool directory (/var/spool/mail) is user-writeable. The user can create hardlinks pointing to root-owned symlinks located in other directories. For a detailed treating of the issue, please refer to the upstream author's announcement. For the stable distribution (etch), this problem has been fixed in version 2.3.8-2+etch1. For the testing distribution (lenny), this problem has been fixed in version 2.5.2-2lenny1. For the unstable distribution (sid), this problem has been fixed in version 2.5.4-1. We recommend that you upgrade your postfix package.
Sebastian Krahmer discovered that Postfix, a mail transfer agent, incorrectly checks the ownership of a mailbox. In some configurations, this allows for appending data to arbitrary files as root.
Note that only specific configurations are vulnerable; the default Debian installation is not affected. Only a configuration meeting the following requirements is vulnerable:
For a detailed treating of the issue, please refer to the upstream author's announcement.
For the stable distribution (etch), this problem has been fixed in version 2.3.8-2+etch4.
For the testing distribution (lenny), this problem has been fixed in version 2.5.2-2lenny1.
For the unstable distribution (sid), this problem has been fixed in version 2.5.4-1.
We recommend that you upgrade your postfix package.
MD5 checksums of the listed files are available in the original advisory.
Vulmon