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Improper Authentication

CVE-2023-2975

Medium
5.3/10

Summary

The AES-SIV cipher implementation contains a bug that causes it to ignore empty associated data entries, which are unauthenticated as a consequence. Applications that use the AES-SIV algorithm and want to authenticate empty data entries as associated data can be misled by removing, adding, or reordering such empty entries as these are ignored by the OpenSSL implementation. We are currently unaware of any such applications. The AES-SIV algorithm allows for the authentication of multiple associated data entries along with the encryption. To authenticate empty data the application has to call "EVP_EncryptUpdate()" (or "EVP_CipherUpdate()") with a NULL pointer as the output buffer and '0' as the input buffer length. The AES-SIV implementation in OpenSSL just returns success for such a call instead of performing the associated data authentication operation. The empty data thus will not be authenticated. As this issue does not affect non-empty associated data authentication and we expect it to be rare for an application to use empty associated data entries this is qualified as Low severity issue. This vulnerability affects openssl versions 3.0.0-alpha1 through 3.0.9, and 3.1.0-alpha1 through 3.1.1.

  • LOW
  • NETWORK
  • LOW
  • UNCHANGED
  • NONE
  • NONE
  • NONE
  • NONE

CWE-287 - Improper Authentication

Improper (or broken) authentication attacks are widespread, and have accounted for many of the worst data breaches in recent years. Improper authentication attacks are a class of vulnerabilities where an attacker impersonates a legitimate user by exploiting weaknesses in either session management or credential management to gain access to the user’s account. This can result in disclosure of sensitive information, and can lead to system compromise, theft, identity theft, and fraud.

References

Advisory Timeline

  • Published