Arbitrary File Overwrite in fwbuilder
Summary
CVE-2008-4956: fwb_install in fwbuilder 2.1.19 allows local users to overwrite arbitrary files via a symlink attack on a /tmp/ssh-agent.##### temporary file. Affects fwbuilder versions < 2.1.19-5. Fixed in 2.1.19-5. How to fix ↓
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Background
fwbuilder is a firewall management tool that allows users to design, configure, and manage firewalls. It provides a graphical interface to create firewall rules and generates the necessary configuration files for various firewall platforms. The vulnerability in fwbuilder version 2.1.19 allows local users to overwrite arbitrary files through a symlink attack on a temporary file created in the /tmp/ssh-agent.##### directory.
Vulnerability Detail
The vulnerability arises from the insecure handling of temporary files by the fwb_install component in fwbuilder. By exploiting a symlink attack, a local user can manipulate the temporary file created by fwb_install in the /tmp/ssh-agent.##### directory. This allows the attacker to overwrite arbitrary files on the system, potentially leading to unauthorized access, data loss, or privilege escalation.
How To Fix
Minimum fixed version
2.1.19-5
This is the first release that contains the fix.
sudo apt-get install --only-upgrade fwbuilderTip — Not sure which version your app runs? Vulert can match this fix to it. Scan free →
Workaround
As a workaround, users can manually create a secure temporary directory for fwbuilder and modify the fwb_install script to use this directory instead of the vulnerable /tmp/ssh-agent.##### directory. This can be achieved by editing the fwb_install script and changing the temporary directory path to a location with restricted access and proper file permissions.
Conclusion
The vulnerability in fwbuilder version 2.1.19 allows local users to overwrite arbitrary files through a symlink attack on a temporary file. It is crucial to upgrade fwbuilder to version 2.1.19-5 or later to mitigate this vulnerability. For further support on vulnerability remediation, you can contact DevNack.com.
See every vulnerability recorded for fwbuilder →
FAQ
fwbuilder is a firewall management tool that provides a graphical interface to design, configure, and manage firewalls.
This vulnerability allows local users to overwrite arbitrary files on the system, potentially leading to unauthorized access, data loss, or privilege escalation.
To fix this vulnerability, it is recommended to upgrade fwbuilder to version 2.1.19-5 or later.
Yes, users can manually create a secure temporary directory for fwbuilder and modify the fwb_install script to use this directory instead of the vulnerable /tmp/ssh-agent.##### directory.
For more information about this vulnerability, you can refer to the official CVE-2008-4956 advisory.
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