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Red Hat Linux Advisory: unzip

Jul 01, 2003, 14:57 (0 Talkback[s])

Red Hat Security Advisory

Synopsis: Updated unzip packages fix trojan vulnerability
Advisory ID: RHSA-2003:199-01
Issue date: 2003-07-01
Updated on: 2003-07-01
Product: Red Hat Linux
Keywords: unzip control characters
Cross references:  
Obsoletes: RHSA-2002:096
CVE Names: CAN-2003-0282

1 .Topic:

Updated unzip packages resolving a vulnerability allowing arbitrary files to be overwritten are now available.

2. Relevant releases/architectures:

Red Hat Linux 7.1 - i386
Red Hat Linux 7.2 - i386, ia64
Red Hat Linux 7.3 - i386
Red Hat Linux 8.0 - i386
Red Hat Linux 9 - i386

3. Problem description:

The unzip utility is used for manipulating archives, which are multiple files stored inside of a single file.

A vulnerabilitiy in unzip version 5.50 and earlier allows attackers to overwrite arbitrary files during archive extraction by placing invalid (non-printable) characters between two "." characters. These non-printable characters are filtered, resulting in a ".." sequence. The Common Vulnerabilities and Exposures project ( has assigned the name CAN-2003-0282 to this issue.

This erratum includes a patch ensuring that non-printable characters do not make it possible for a malicious .zip file to write to parent directories unless the "-:" command line parameter is specified.

Users of unzip are advised to upgrade to these updated packages, which are not vulnerable to this issue.

4. Solution:

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

To update all RPMs for your particular architecture, run:

rpm -Fvh [filenames]

where [filenames] is a list of the RPMs you wish to upgrade. Only those RPMs which are currently installed will be updated. Those RPMs which are not installed but included in the list will not be updated. Note that you can also use wildcards (*.rpm) if your current directory only contains the desired RPMs.

Please note that this update is also available via Red Hat Network. Many people find this an easier way to apply updates. To use Red Hat Network, launch the Red Hat Update Agent with the following command:


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

5. Bug IDs fixed ( for more info):

97301 - vulnerability in unzip 5.50 allows malicious zip file to write to ../

6. RPMs required:

Red Hat Linux 7.1:



Red Hat Linux 7.2:




Red Hat Linux 7.3:



Red Hat Linux 8.0:



Red Hat Linux 9:



7. Verification:

MD5 sum Package Name

627c65d2643152f360a4b7f8ebacf993 7.1/en/os/SRPMS/unzip-5.50-11.src.rpm
c37b3635f768ca248ef6486f38a4cfb1 7.1/en/os/i386/unzip-5.50-11.i386.rpm
627c65d2643152f360a4b7f8ebacf993 7.2/en/os/SRPMS/unzip-5.50-11.src.rpm
c37b3635f768ca248ef6486f38a4cfb1 7.2/en/os/i386/unzip-5.50-11.i386.rpm
e1cb9d0c5312667c601e3a04e160ea3c 7.2/en/os/ia64/unzip-5.50-11.ia64.rpm
627c65d2643152f360a4b7f8ebacf993 7.3/en/os/SRPMS/unzip-5.50-11.src.rpm
c37b3635f768ca248ef6486f38a4cfb1 7.3/en/os/i386/unzip-5.50-11.i386.rpm
b06d287ae9708615d9c8201addd84ceb 8.0/en/os/SRPMS/unzip-5.50-12.src.rpm
14e662c115aab0fd073602a2637c306a 8.0/en/os/i386/unzip-5.50-12.i386.rpm
da4837981a5363b178185c3d53bfe3f5 9/en/os/SRPMS/unzip-5.50-14.src.rpm
12b5697f11ad09959e9f51d570c37268 9/en/os/i386/unzip-5.50-14.i386.rpm

These packages are GPG signed by Red Hat for security. Our key is available from

You can verify each package with the following command:

rpm --checksig -v <filename>

If you only wish to verify that each package has not been corrupted or tampered with, examine only the md5sum with the following command:

md5sum <filename>

8. References:

9. Contact:

The Red Hat security contact is <>. More contact details at

Copyright 2003 Red Hat, Inc.