Bug 218480

Summary: CVE-2006-6235 GnuPG references local variable after function returns
Product: Red Hat Enterprise Linux 4 Reporter: Lubomir Kundrak <lkundrak>
Component: gnupgAssignee: Nalin Dahyabhai <nalin>
Status: CLOSED ERRATA QA Contact:
Severity: high Docs Contact:
Priority: urgent    
Version: 4.4Keywords: Security
Target Milestone: ---   
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard: impact=important,source=vendor-sec,reported=20061204
Fixed In Version: RHSA-2006-0754 Doc Type: Bug Fix
Doc Text:
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Clone Of: Environment:
Last Closed: 2006-12-06 17:54:01 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
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Description Flags
Proposed fix (for 1.4.5) none

Description Lubomir Kundrak 2006-12-05 18:13:34 UTC 
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


How reproducible:

No reproducer.
Comment 1 Lubomir Kundrak 2006-12-05 18:13:34 UTC 
Created attachment 142874 [details]
Proposed fix (for 1.4.5)
Comment 2 Lubomir Kundrak 2006-12-05 18:36:11 UTC 
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.
Comment 6 Red Hat Bugzilla 2006-12-06 17:54:02 UTC 
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.

http://rhn.redhat.com/errata/RHSA-2006-0754.html