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[HV-MED] Zip/Linux long path buffer overflow
From: vuln () hexview com
Date: Wed, 3 Nov 2004 15:11:29 -0800
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Zip/Linux long path buffer overflow
Zip console application by Info-Zip (http://www.info-zip.org) is an
open-source software and part of many Linux distributions.
A buffer overflow condition can be triggered and exploited during
recursive compression operation.
HexView tested the issue using Zip 2.3 which comes as "zip" package
with Debian Linux. Possibly all earlier Info-Zip versions are vulnerable.
Info-Zip applications for other operating systems are also vulnerable,
but depending on operating system and file system restrictions, the
vulnerability may or may not be triggered or exploited.
Cause and Effect:
When zip performs recursive folder compression, it does not check
for the length of resulting path. If the path is too long, a buffer
overflow occurs leading to stack corruption and segmentation fault.
It is possible to exploit this vulnerability by embedding a shellcode
in directory or file name. While the issue is not of primary concern
for regular users, it can be critical for environments where zip archives
are re-compressed automatically using Info-Zip application.
The issue can be reproduced by following these steps:
1. Create an 8-level directory structure, where each directory name is
256 characters long (we used 256 'a' characters).
2. run "zip -r file.zip *". The application will crash with
3. run "gdb -core core `which zip`" (assuming core drop is enabled)
4. type "where" and hit Enter. Here is what you'll see:
Program terminated with signal 11, Segmentation fault.
#0 0x0805108e in error ()
#1 0x61616161 in ?? ()
#2 0x61616161 in ?? ()
#3 0x61616161 in ?? ()
HexView tried to notify vendor using vendor-provided e-mail address
(zip-bugs () lists wku edu) on 2004-10-03. The mail was returned back
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Feedback and comments:
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- [HV-MED] Zip/Linux long path buffer overflow vuln (Nov 03)