First published: Fri Jul 14 2023(Updated: )
Issue summary: The AES-SIV cipher implementation contains a bug that causes it to ignore empty associated data entries which are unauthenticated as a consequence. Impact summary: Applications that use the AES-SIV algorithm and want to authenticate empty data entries as associated data can be mislead 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 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 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. <a href="https://git.openssl.org/gitweb/?p=openssl.git;a=commitdiff;h=6a83f0c958811f07e0d11dfc6b5a6a98edfd5bdc">https://git.openssl.org/gitweb/?p=openssl.git;a=commitdiff;h=6a83f0c958811f07e0d11dfc6b5a6a98edfd5bdc</a> <a href="https://www.openssl.org/news/secadv/20230714.txt">https://www.openssl.org/news/secadv/20230714.txt</a> <a href="https://git.openssl.org/gitweb/?p=openssl.git;a=commitdiff;h=00e2f5eea29994d19293ec4e8c8775ba73678598">https://git.openssl.org/gitweb/?p=openssl.git;a=commitdiff;h=00e2f5eea29994d19293ec4e8c8775ba73678598</a> This has not been included in a specific release but has been added to the master, 3.1, and 3.0 branches <a href="https://github.com/openssl/openssl/pull/21384">https://github.com/openssl/openssl/pull/21384</a>
Affected Software | Affected Version | How to fix |
---|---|---|
OpenSSL | >=3.0.0<3.1.0 |
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The severity of REDHAT-BUG-2223016 is critical due to potential authentication vulnerabilities in AES-SIV implementations.
To fix REDHAT-BUG-2223016, upgrade OpenSSL to version 3.1.0 or later.
OpenSSL versions between 3.0.0 and 3.1.0 are affected by REDHAT-BUG-2223016.
The impact of REDHAT-BUG-2223016 is that applications may incorrectly handle empty associated data entries, resulting in unauthenticated data.
Yes, if your application uses the AES-SIV cipher in affected OpenSSL versions, it is vulnerable to REDHAT-BUG-2223016.