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+---
+layout: post
+title: "buf.pl update available"
+---
+
+An information disclosure vulnerability was found, reported and fixed
+in the buf.pl script by its author.
+
+CWE Classification: CWE-732, CWE-538
+
+### Impact
+
+Other users on the same machine may be able to retrieve the whole
+window contents after /UPGRADE when the buf.pl script is
+loaded. Furthermore, this dump of the windows contents is never
+removed afterwards.
+
+Since buf.pl is also an Irssi core script and we recommended its use
+to retain your window content, many people could potentially be
+affected by this.
+
+Remote users may be able to retrieve these contents when combined with
+other path traversal vulnerabilities in public facing services on that
+machine.
+
+### Detailed analysis
+
+buf.pl restores the scrollbuffer between "/upgrade"s by writing the
+contents to a file, and reading that after the new process was spawned.
+Through that file, the contents of (private) chat conversations may leak to
+other users.
+
+### Mitigating facts
+
+Careful users with a limited umask (e.g. 077) are not affected by this bug.
+However, most Linux systems default to a umask of 022, meaning that files
+written without further restricting the permissions, are readable by any
+user.
+
+### Affected versions
+
+All up to 2.13
+
+### Fixed versions
+
+[buf.pl](//scripts.irssi.org/scripts/buf.pl) 2.20
+
+### Resolution
+
+Update the buf.pl script with the latest version from
+[scripts.irssi.org](//scripts.irssi.org).
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