Summary

Security Advisory ID : BSA-2022-1586

Component : OpenSSL

Revision : 2.0

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_decrypt() is called by the application a second time with a buffer that is too small. A malicious attacker who is able present SM2 content for decryption to an application could cause attacker chosen data to overflow the buffer by up to a maximum of 62 bytes altering the contents of other data held after the buffer, possibly changing application behaviour or causing the application to crash. The location of the buffer is application dependent but is typically heap allocated. Fixed in OpenSSL 1.1.1l (Affected 1.1.1-1.1.1k).

Notes:

Brocade Fabric OS does not utilize SM2 encryption. Brocade Fabric OS is Not Affected by this vulnerability. Security updates are provided in Brocade Fabric OS versions v9.1.0 and v9.0.1e to remove the vulnerable component

Brocade SANnav does not utilize SM2 encryption. Brocade SANnav is Not Affected by this vulnerability. Security updates to remove the vulnerable component will be provided in a future release.

Products Confirmed Not Vulnerable

No other Brocade Fibre Channel Products from Broadcom products are known to be affected by this vulnerability.

Solution

A security update was provided in Brocade Fabric OS v9.1.0 and v9.0.1e to remove the vulnerable components.

Revision History