A security issue and a vulnerability have been reported in ARC, which can be exploited by malicious, local users to gain access to sensitive information and perform certain actions on a vulnerable system with escalated privileges.

1) The security issue is caused due to new archives being created in "/tmp" by "arc" and "marc" before being renamed to the user specified filename. This can be exploited to read the contents of the archive before it is moved.

Successful exploitation requires that the ARCTEMP environment variable is not defined.

2) An error where temporary files are created insecurely in "arcsvc.c" can be exploited via symlink attacks to overwrite arbitrary files with the privileges of the user running ARC.

The security issue and the vulnerability have been reported in version 5.21l. Prior versions may also be affected.

Solution
Update to version 5.21m.
Further details available to Secunia VIM customers

Provided and/or discovered by
1) D1g1t4lLeech
2) Joey Schulze

Changelog
Further details available to Secunia VIM customers

Original Advisory
http://www.debian.org/security/2005/dsa-843

Deep Links
Links available to Secunia VIM customers