Critical Vulnerability in Ghostscript: Bypass of .tempfile Restrictions
Summary
ALPINE-CVE-2018-15908: In Artifex Ghostscript 9.23 before 2018-08-23, attackers are able to supply malicious PostScript files to bypass .tempfile restrictions and write files. Affects ghostscript versions < 9.24-r0. Fixed in 9.24-r0. How to fix ↓
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Background
Ghostscript is an interpreter for the PostScript language and for PDF. It is widely used for processing and rendering documents in various formats. The software is known for its ability to convert files between different formats and is often utilized in printing and document management systems. However, Ghostscript has been found to have a vulnerability that allows attackers to exploit its handling of PostScript files, leading to potential unauthorized file access.
Vulnerability Detail
In Artifex Ghostscript version 9.23, prior to August 23, 2018, a vulnerability exists that allows attackers to supply malicious PostScript files. This can bypass the .tempfile restrictions, enabling unauthorized file writing. The implications of this vulnerability are severe, as it can lead to data leakage, unauthorized access to sensitive files, and potential system compromise. The vulnerability is classified with a CVSS score of 7.8, indicating a high severity level.
How To Fix
Minimum fixed version
9.24-r0
This is the first release that contains the fix.
sudo apk add --upgrade ghostscriptTip — Not sure which version your app runs? Vulert can match this fix to it. Scan free →
Workaround
As a temporary workaround, avoid processing untrusted PostScript files until the package is updated. Implement strict validation of input files to mitigate the risk of exploitation.
Conclusion
The vulnerability in Ghostscript poses a significant risk due to its ability to allow unauthorized file access through malicious PostScript files. It is crucial to update to the patched version to mitigate this risk. Users should also consider implementing workarounds until the update can be applied.
See every vulnerability recorded for ghostscript →
FAQ
The vulnerability allows attackers to bypass .tempfile restrictions by supplying malicious PostScript files, leading to unauthorized file writing.
You can use the Vulert playground at Vulert Scanner to check if your application is affected by this vulnerability without needing to sign up.
The CVSS score of this vulnerability is 7.8, indicating a high severity level.
If immediate updates are not possible, avoid processing untrusted PostScript files and implement strict input validation as a temporary measure.
You can find more information on the official Ghostscript website and security advisories related to the software.
References
Related vulnerabilities
Recent vulnerabilities recorded for ghostscript.
