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CVE-2021-3711
CRITICAL · CVSS 9.8
EPSS exploitation probability: 0%
Published 2021-08-24T15:15:09.133 · Last modified 2026-06-17T04:05:36.467

Summary

In order to decrypt SM2 encrypted data an application is expected to call the API function EVP_PKEY_decrypt(). Typically an application will call this function twice. The first time, on entry, the "out" parameter can be NULL and, on exit, the "outlen" parameter is populated with the buffer size required to hold the decrypted plaintext. The application can then allocate a sufficiently sized buffer and call EVP_PKEY_decrypt() again, but this time passing a non-NULL value for the "out" parameter. A bug in the implementation of the SM2 decryption code means that the calculation of the buffer size required to hold the plaintext returned by the first call to EVP_PKEY_decrypt() can be smaller than the actual size required by the second call. This can lead to a buffer overflow when EVP_PKEY_decryp

Affected products

openssl — openssl

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References

This product uses data from the NVD API but is not endorsed or certified by the NVD. Informational only; not professional security advice.