RHSA-2002:256 - Security Advisory

Topic

The wget packages shipped with Red Hat Linux Advanced Server 2.1 contain a
security bug which, under certain circumstances, can cause local files to
be written outside the download directory.

[Updated 09 Jan 2003]
Added fixed packages for the Itanium (IA64) architecture.

[Updated 06 Feb 2003]
Added fixed packages for Advanced Workstation 2.1

Description

Versions of wget prior to 1.8.2-4 contain a bug that permits a malicious
FTP server to create or overwrite files anywhere on the local file system.

FTP clients must check to see if an FTP server's response to the NLST
command includes any directory information along with the list of filenames
required by the FTP protocol (RFC 959, section 4.1.3).

If the FTP client fails to do so, a malicious FTP server can send filenames
beginning with '/' or containing '/../' which can be used to direct a
vulnerable FTP client to write files (such as .forward, .rhosts, .shost,
etc.) that can then be used for later attacks against the client machine.

All users of wget should upgrade to the errata packages which are not
vulnerable to this issue.

Thanks to Steven M. Christey for his work in discovering this issue
in current FTP clients and for providing a patched FTP server to verify
the new packages.

Solution

Before applying this update, make sure all previously released errata
relevant to your system have been applied.

Please note that this update is available via Red Hat Network. To use Red
Hat Network, launch the Red Hat Update Agent with the following command:

up2date

This will start an interactive process that will result in the appropriate
RPMs being upgraded on your system.

Affected Products

• Red Hat Enterprise Linux Server 2 ia64
• Red Hat Enterprise Linux Workstation 2 ia64

Fixes

CVEs

• CVE-2002-1344

References

(none)