Input validation error in linux-pam - CVE-2010-3435

Detailed vulnerability description

The vulnerability allows a remote non-authenticated attacker to gain access to sensitive information.

The (1) pam_env and (2) pam_mail modules in Linux-PAM (aka pam) before 1.1.2 use root privileges during read access to files and directories that belong to arbitrary user accounts, which might allow local users to obtain sensitive information by leveraging this filesystem activity, as demonstrated by a symlink attack on the .pam_environment file in a user's home directory.

How to mitigate CVE-2010-3435

Sources

• http://git.altlinux.org/people/ldv/packages/?p=pam.git;a=commit;h=06f882f30092a39a1db867c9744b2ca8d60e4ad6
• http://lists.vmware.com/pipermail/security-announce/2011/000126.html
• http://openwall.com/lists/oss-security/2010/09/21/3
• http://openwall.com/lists/oss-security/2010/09/27/10
• http://openwall.com/lists/oss-security/2010/09/27/4
• http://openwall.com/lists/oss-security/2010/09/27/5
• http://openwall.com/lists/oss-security/2010/09/27/7
• http://openwall.com/lists/oss-security/2010/09/27/8
• http://openwall.com/lists/oss-security/2010/10/25/2
• http://secunia.com/advisories/49711
• http://security.gentoo.org/glsa/glsa-201206-31.xml
• http://www.mandriva.com/security/advisories?name=MDVSA-2010:220
• http://www.openwall.com/lists/oss-security/2010/09/24/2
• http://www.redhat.com/support/errata/RHSA-2010-0819.html
• http://www.redhat.com/support/errata/RHSA-2010-0891.html
• http://www.securityfocus.com/archive/1/516909/100/0/threaded
• http://www.vmware.com/security/advisories/VMSA-2011-0004.html
• http://www.vupen.com/english/advisories/2011/0606
• https://bugzilla.redhat.com/show_bug.cgi?id=641335