The _dl_unsetenv function in loader.c in the ELF ld.so in...

Vulnerability Description

The _dl_unsetenv function in loader.c in the ELF ld.so in OpenBSD 3.9 and 4.0 does not properly remove duplicate environment variables, which allows local users to pass dangerous variables such as LD_PRELOAD to loading processes, which might be leveraged to gain privileges.

References

• http://www.openbsd.org/errata39.html#ldso
• http://www.matasano.com/log/592/finger-79tcp-mcdonald-dowd-and-schuh-challenge-part-2/
• http://www.securityfocus.com/archive/1/452428/100/0/threaded
• http://secunia.com/advisories/22993
• http://www.securityfocus.com/bid/21188
• http://www.openbsd.org/errata.html#ldso
• http://www.securityfocus.com/archive/1/452371/100/0/threaded
• http://securitytracker.com/id?1017253
• https://exchange.xforce.ibmcloud.com/vulnerabilities/30441