Red Hat Bugzilla – Bug 218480
CVE-2006-6235 GnuPG references local variable after function returns
Last modified: 2007-11-16 20:14:54 EST
Description of problem:
Reference to local variable dfx of function decrypt_data() is used by the
functions decode_filter() and mdc_decode_filter() after it is terminated,
making it possible to overwrite the stack by changing its contents, which can
potentially lead to arbitrairy code execution (when program flow is altered
by overwriting the return address stored on the stack)
Version-Release number of selected component (if applicable):
RHEL-2.1, RHEL-3, RHEL-4, RHEL-5, FC-5, FC-6
Created attachment 142874 [details]
Proposed fix (for 1.4.5)
The description is wrong. It is actually not possible to overwrite stack with
reference to the structure, but the opposite -- modify the structure by changing
some local variable in function, whose stack frame covers the structure.
This is dangerous, because the structure containst pointers to functions.
An advisory has been issued which should help the problem
described in this bug report. This report is therefore being
closed with a resolution of ERRATA. For more information
on the solution and/or where to find the updated files,
please follow the link below. You may reopen this bug report
if the solution does not work for you.