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Red Hat Linux Advisory: unzip

Aug 15, 2003, 15:51 (0 Talkback[s])

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Red Hat Security Advisory

Synopsis: Updated unzip packages fix trojan vulnerability
Advisory ID: RHSA-2003:199-02
Issue date: 2003-07-01
Updated on: 2003-08-15
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.

[Updated 15 August 2003]
Ben Laurie found that the original patch to fix this issue missed a case where the path component included a quoted slash. These updated packages contain a new patch that corrects this issue.

2. Relevant releases/architectures:

Red Hat Linux 7.1 - i386
Red Hat Linux 7.1 for iSeries (64 bit) - ppc
Red Hat Linux 7.1 for pSeries (64 bit) - ppc
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 7.1 for iSeries (64 bit):



Red Hat Linux 7.1 for pSeries (64 bit):



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

7726fd0a5026763537b7d947e84fa8a5 7.1/en/os/SRPMS/unzip-5.50-31.src.rpm
5528f5705d056ceeda5ad97e6ade46f8 7.1/en/os/i386/unzip-5.50-31.i386.rpm
7726fd0a5026763537b7d947e84fa8a5 7.1/en/os/iSeries/SRPMS/unzip-5.50-31.src.rpm
1b56998c114550b761819d63bd5ced3e 7.1/en/os/iSeries/ppc/unzip-5.50-31.ppc.rpm
7726fd0a5026763537b7d947e84fa8a5 7.1/en/os/pSeries/SRPMS/unzip-5.50-31.src.rpm
1b56998c114550b761819d63bd5ced3e 7.1/en/os/pSeries/ppc/unzip-5.50-31.ppc.rpm
7726fd0a5026763537b7d947e84fa8a5 7.2/en/os/SRPMS/unzip-5.50-31.src.rpm
5528f5705d056ceeda5ad97e6ade46f8 7.2/en/os/i386/unzip-5.50-31.i386.rpm
451f973b77c2ced03d344495774cd253 7.2/en/os/ia64/unzip-5.50-31.ia64.rpm
7726fd0a5026763537b7d947e84fa8a5 7.3/en/os/SRPMS/unzip-5.50-31.src.rpm
5528f5705d056ceeda5ad97e6ade46f8 7.3/en/os/i386/unzip-5.50-31.i386.rpm
a16d8797347c730ad0f2e6892f881eb3 8.0/en/os/SRPMS/unzip-5.50-32.src.rpm
e708a3b370ec0febd115dca3dd4da0f4 8.0/en/os/i386/unzip-5.50-32.i386.rpm
5b4b902fde88ab017acb2c0c7f48b2c2 9/en/os/SRPMS/unzip-5.50-33.src.rpm
e6d52c854a8ebba7dacb678a5edb5cb8 9/en/os/i386/unzip-5.50-33.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.