REDHAT-BUG-1228571: Medium severity suse pam vulnerability
From the original report: "If SELinux is enabled, the unixrunhelperbinary function in Linux-PAM 1.1.8 and earlier hangs indefinitely when verifying a password of 65536 characters, which allows attackers to conduct username enumeration and denial of service attacks.
When supplying a password of 65536 characters or more, the process will block on the write(2) call at modules/pamunix/support.c:614 because it tries to write strlen(passwd)+1 bytes to a blocking pipe and a pipe has a limited capacity of 65536 bytes on Linux."
Acknowledgements:
Red Hat would like to thank Sebastien Macke of Trustwave SpiderLabs for reporting this issue.
Affected Software
Event History
Frequently Asked Questions
What is the severity of REDHAT-BUG-1228571?
The vulnerability REDHAT-BUG-1228571 allows for potential username enumeration and denial of service attacks.
How do I fix REDHAT-BUG-1228571?
To resolve REDHAT-BUG-1228571, upgrade Linux-PAM to version 1.1.9 or later.
What causes REDHAT-BUG-1228571?
REDHAT-BUG-1228571 is caused by the _unix_run_helper_binary function hanging indefinitely with excessively long passwords.
Who is affected by REDHAT-BUG-1228571?
Any system using Linux-PAM version 1.1.8 or earlier with SELinux enabled is vulnerable to REDHAT-BUG-1228571.
What impacts does REDHAT-BUG-1228571 have on systems?
The main impacts of REDHAT-BUG-1228571 include potential denial of service and increased risk of username enumeration.