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CERT Coordination Center


GnuPG contains format-string vulnerability in handling of encrypted data filename

Vulnerability Note VU#233200

Original Release Date: 2002-03-29 | Last Revised: 2002-03-29

Overview

Some versions of Gnu Privacy Guard (GPG) contain a format-string vulnerability from improper handling of filenames when decrypting files.

Description

GPG is an OpenPGP-compliant alternative to PGP to protect electronic communications using public-key cryptography. Versions of GPG prior to 1.0.6 contain a format-string vulnerability.

The GPG source includes a function named tty_printf(), which expects as parameters -- much like the standard C library function printf() -- a format string followed by data values as indicated in the format string. The do_get() function in file util/ttyio.c of the GPG source code makes a call to tty_printf(), passing the filename as the format string instead of passing a constant format string followed by a pointer to the filename.

Impact

Attackers can craft a filename for an encrypted file that will cause GPG to execute arbitrary code when the file is decrypted by the recipient, with the privileges of the recipient user.

Solution

Upgrade GPG to version 1.0.6, available from:

http://www.gnupg.org

Until a patch can be applied, do not decrypt messages from untrusted sources with GPG.

Vendor Information

233200
Expand all

Free Software Foundation

Updated:  March 29, 2002

Status

  Vulnerable

Vendor Statement

See http://www.gnupg.org/whatsnew.html#rn20010529

Vendor Information

The vendor has not provided us with any further information regarding this vulnerability.

Addendum

The CERT/CC has no additional comments at this time.

If you have feedback, comments, or additional information about this vulnerability, please send us email.


CVSS Metrics

Group Score Vector
Base N/A N/A
Temporal N/A N/A
Environmental N/A

References

Credit

Thanks to fish stiqz for reporting this vulnerability.

This document was written by Shawn Van Ittersum.

Other Information

CVE IDs: CVE-2001-0522
Severity Metric: 5.83
Date Public: 2001-05-29
Date First Published: 2002-03-29
Date Last Updated: 2002-03-29 22:59 UTC
Document Revision: 9

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