Stack-buffer-underflow in gs_type2_interpret in ghostscript
Summary
OSV-2022-1021: Stack-buffer-underflow in gs_type2_interpret. Affects ghostscript versions >= 441c9e3a4ca08fa7f7c00063af33196b0d88ebaf, < b7f934c26b6d139d665ab924167036c74a973360. Fixed in b7f934c26b6d139d665ab924167036c74a973360. 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 documents. The vulnerability in question, identified as OSV-2022-1021, is a stack-buffer-underflow issue that affects the gs_type2_interpret function in Ghostscript. This function is responsible for interpreting Type 2 fonts, which are commonly used in PDF files. The vulnerability can be triggered when processing a specially crafted Type 2 font, leading to a stack-buffer-underflow read of 4 bytes.
Vulnerability Detail
The stack-buffer-underflow vulnerability in gs_type2_interpret can result in the reading of 4 bytes beyond the bounds of the stack buffer. This can potentially lead to memory corruption and arbitrary code execution. An attacker could exploit this vulnerability by crafting a malicious PDF file with a specially crafted Type 2 font and tricking a user into opening it. Successful exploitation of this vulnerability could allow the attacker to execute arbitrary code on the affected system with the privileges of the Ghostscript process.
How To Fix
Minimum fixed version
b7f934c26b6d139d665ab924167036c74a973360
This is the first release that contains the fix.
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Workaround
As a workaround, users can consider disabling the processing of Type 2 fonts in Ghostscript. This can be achieved by modifying the Ghostscript configuration file to remove the Type 2 font interpreter. However, this workaround may impact the rendering and processing of certain PDF files that rely on Type 2 fonts.
Conclusion
In conclusion, the stack-buffer-underflow vulnerability in gs_type2_interpret in Ghostscript can be exploited by crafting a malicious PDF file with a specially crafted Type 2 font. This can lead to memory corruption and arbitrary code execution. It is recommended to update Ghostscript to a version that includes the fix for this vulnerability. Alternatively, users can consider disabling the processing of Type 2 fonts as a temporary workaround. For further support on vulnerability remediation, please contact DevNack.com.
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FAQ
Ghostscript is an open-source interpreter for the PostScript language and the PDF file format. It is commonly used for rendering and converting documents.
A stack-buffer-underflow vulnerability occurs when a program reads data from a stack buffer beyond its bounds, potentially leading to memory corruption and arbitrary code execution.
This vulnerability can be exploited by crafting a malicious PDF file with a specially crafted Type 2 font and tricking a user into opening it.
Successful exploitation of this vulnerability could allow an attacker to execute arbitrary code on the affected system with the privileges of the Ghostscript process.
Yes, this vulnerability has been fixed in the Ghostscript Git repository in commit b7f934c26b6d139d665ab924167036c74a973360. Users should update their installations to a version that includes this fix.
References
Related vulnerabilities
Recent vulnerabilities recorded for ghostscript.
