OpenSC Stack Buffer Overflow Vulnerability (CVE-2025-49010)

A stack buffer overflow vulnerability, identified as CVE-2025-49010, exists in the GET RESPONSE function of OpenSC. The vulnerability allows an attacker to overwrite data on the stack, potentially leading to arbitrary code execution. While the specific exploitation details are not provided in the initial advisory, the nature of a stack buffer overflow indicates a high risk, especially if OpenSC is used in security-sensitive applications or environments. Successful exploitation could allow an attacker to gain control of the affected system or application, potentially leading to data theft, system compromise, or denial of service. Given the lack of specifics, defenders should prioritize patching and monitoring for exploitation attempts.

Attack Chain

1. An attacker crafts a malicious smart card or manipulates input data to be processed by OpenSC.
2. The malicious data is passed to the GET RESPONSE function within OpenSC.
3. The GET RESPONSE function attempts to process the data without proper bounds checking.
4. Due to the lack of bounds checking, a stack buffer overflow occurs when writing data.
5. The overflow overwrites adjacent memory locations on the stack.
6. The overwritten memory includes return addresses or other critical data.
7. When the GET RESPONSE function returns, execution is redirected to an address controlled by the attacker.
8. The attacker executes arbitrary code, potentially gaining control of the system.

Impact

Successful exploitation of CVE-2025-49010 allows an attacker to execute arbitrary code on the affected system. The number of victims and sectors targeted are currently unknown. If exploited, this vulnerability could lead to complete system compromise, data theft, or denial of service. Given the nature of OpenSC, which is used for smart card access, successful exploitation may allow an attacker to compromise cryptographic keys and other sensitive information.

Recommendation

• Apply the security patch for CVE-2025-49010 as soon as it becomes available from the vendor.
• Implement runtime stack protection mechanisms to detect and prevent stack buffer overflows.
• Deploy the Sigma rule to monitor for suspicious process execution after OpenSC function calls.
• Enable verbose logging for OpenSC to capture details about function calls and data processing to facilitate investigation.