Screen: UTF-8 character handling vulnerability — GLSA 200611-01

Screen contains an error in its UTF-8 character handling code that would allow a remote Denial of Service or possibly the remote execution of arbitrary code.

Affected Packages

app-misc/screen on all architectures
Affected versions < 4.0.3
Unaffected versions >= 4.0.3

Background

Screen is a full-screen window manager that multiplexes a physical terminal between several processes, typically interactive shells.

Description

cstone and Richard Felker discovered a flaw in Screen's UTF-8 combining character handling.

Impact

The vulnerability can be exploited by writing a special string of characters to a Screen window. A remote attacker could cause a Denial of Service or possibly execute arbitrary code with the privileges of the user running Screen through a program being run inside a Screen session, such as an IRC client or a mail client.

Workaround

There is no known workaround at this time.

Resolution

All Screen users should upgrade to the latest version:

 # emerge --sync
 # emerge --ask --oneshot --verbose ">=app-misc/screen-4.0.3"

References

Release Date
November 03, 2006

Latest Revision
November 03, 2006: 01

Severity
high

Exploitable
remote

Bugzilla entries