Stack Buffer Overflow Vulnerability in OpenSC Package
Summary
OSV-2026-824: Stack-buffer-overflow in coolkey_rsa_op. Affects opensc versions >= 7d5d10ef37806d408cc8871026faec7f8c069991, < b25b78845e8a5983d9c1bd96d34b3c89e00f07fd. Fixed in b25b78845e8a5983d9c1bd96d34b3c89e00f07fd. How to fix ↓
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Background
OpenSC is an open-source project that provides a set of libraries and utilities for smart cards and other cryptographic tokens. It enables secure access to various cryptographic operations, including digital signatures and encryption. However, a recent vulnerability has been identified in the coolkey_rsa_op function, which could lead to a stack buffer overflow, potentially compromising the security of applications relying on this package.
Vulnerability Detail
The vulnerability stems from a stack buffer overflow in the coolkey_rsa_op function, as reported by OSS-Fuzz. This issue occurs during the computation of cryptographic signatures, where improper handling of input data can lead to memory corruption. If exploited, this vulnerability could allow an attacker to execute arbitrary code or crash the application, posing significant risks to data integrity and confidentiality.
How To Fix
Minimum fixed version
b25b78845e8a5983d9c1bd96d34b3c89e00f07fd
This is the first release that contains the fix.
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Workaround
As a temporary workaround, users can avoid using the coolkey_rsa_op function until they can update to the patched version. Additionally, implementing input validation to ensure that data passed to cryptographic functions is properly sized may help mitigate the risk of exploitation.
Conclusion
The stack buffer overflow vulnerability in the OpenSC package poses significant risks to applications utilizing its cryptographic functions. It is crucial for users to update to the patched version to mitigate these risks. Implementing temporary workarounds can provide additional protection until the update is applied.
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FAQ
A stack buffer overflow occurs when a program writes more data to a buffer located on the stack than it can hold, leading to memory corruption and potential exploitation.
If your application uses the OpenSC package and relies on the vulnerable coolkey_rsa_op function, it may be susceptible to crashes or arbitrary code execution by an attacker.
Yes, you can use Vulert, which monitors and alerts for open-source vulnerabilities in your software. You can check if your application is affected by this vulnerability using the Vulert playground at Vulert Scanner without needing to sign up.
If an immediate update is not possible, consider implementing input validation as a temporary measure to reduce the risk of exploitation until you can apply the patch.
More details can be found in the OSS-Fuzz report linked in the vulnerability details, which provides insights into the crash state and technical aspects of the issue.
References
Related vulnerabilities
Recent vulnerabilities recorded for opensc.
