Heap-use-after-free vulnerability in ghostscript
Summary
OSV-2021-1692: Heap-use-after-free in chunk_free_object. Affects ghostscript versions >= 75fbddf52051987287e62d13c659eb73ba16982f, < 7fe54b1dbf221864b25ff55eccf1d624c07bb21d. Fixed in 7fe54b1dbf221864b25ff55eccf1d624c07bb21d. How to fix ↓
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Background
Ghostscript is an open-source interpreter for the PostScript language and the PDF file format. It is widely used for rendering and converting PDF files. The vulnerability identified in Ghostscript is a heap-use-after-free issue, which occurs when a program attempts to access memory that has already been freed. This vulnerability can be exploited by an attacker to execute arbitrary code or cause a denial-of-service condition.
Vulnerability Detail
The heap-use-after-free vulnerability in Ghostscript is triggered during the execution of the 'chunk_free_object' function. This function is responsible for freeing memory chunks used by the program. However, due to a programming error, the function does not properly handle certain scenarios, leading to a use-after-free condition. An attacker can exploit this vulnerability by crafting a malicious PDF file and tricking a user into opening it with a vulnerable version of Ghostscript. Upon opening the file, the attacker can execute arbitrary code or crash the application, potentially leading to further compromise of the system.
How To Fix
Minimum fixed version
7fe54b1dbf221864b25ff55eccf1d624c07bb21d
This is the first release that contains the fix.
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Workaround
As a temporary workaround, users can consider disabling the processing of untrusted PDF files in Ghostscript. This can be achieved by configuring the application to only process PDF files from trusted sources or by using alternative PDF rendering software until a patched version of Ghostscript is available.
Conclusion
The heap-use-after-free vulnerability in Ghostscript poses a significant risk to systems running vulnerable versions of the software. It is crucial to update to the latest version of Ghostscript that includes the fix for this vulnerability. Additionally, following best practices for secure coding and regularly updating software dependencies can help mitigate the risk of similar vulnerabilities. For further support on vulnerability remediation, you can reach out to DevNack.com.
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FAQ
A heap-use-after-free vulnerability occurs when a program attempts to access memory that has already been freed. This can lead to unexpected behavior, crashes, or potential code execution by an attacker.
An attacker can exploit this vulnerability by crafting a malicious PDF file and tricking a user into opening it with a vulnerable version of Ghostscript. Upon opening the file, the attacker can execute arbitrary code or crash the application.
Yes, this vulnerability has been fixed in the latest version of Ghostscript. Users are advised to update their installations to a version that includes the fix.
As a temporary workaround, users can consider disabling the processing of untrusted PDF files in Ghostscript or using alternative PDF rendering software until a patched version is available.
If you suspect your system is affected, it is recommended to update Ghostscript to the latest version and follow the provided mitigation steps. You can also use Vulert Playground (https://vulert.com/scanner) to check if your application is affected by this vulnerability.
References
Related vulnerabilities
Recent vulnerabilities recorded for ghostscript.
