CVE-2023-2975

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.

Read the notes from the security team

Why is this CVE low priority?

Upstream OpenSSL have rated this issue as being low severity

Learn more about Ubuntu priority

Status

Show unmaintained releases

Package	Ubuntu Release	Status
edk2	24.10 oracular	Not affected
	24.04 LTS noble	Not affected
	23.10 mantic	Not affected
	23.04 lunar	Not affected
	22.10 kinetic	Not affected
	22.04 LTS jammy	Not affected
	20.04 LTS focal	Not affected
	18.04 LTS bionic	Not affected
	16.04 LTS xenial	Not affected
	14.04 LTS trusty	Ignored end of standard support
nodejs	24.10 oracular	Not affected
	24.04 LTS noble	Not affected
	23.10 mantic	Not affected
	23.04 lunar	Not affected
	22.10 kinetic	Not affected
	22.04 LTS jammy	Vulnerable
	20.04 LTS focal	Not affected
	18.04 LTS bionic	Needs evaluation
	16.04 LTS xenial	Needs evaluation
	14.04 LTS trusty	Not affected
openssl	24.10 oracular	Not affected
	24.04 LTS noble	Not affected
	23.10 mantic	Not affected
	23.04 lunar	Fixed 3.0.8-1ubuntu1.4
	22.10 kinetic	Ignored end of life, was needed
	22.04 LTS jammy	Fixed 3.0.2-0ubuntu1.12
	20.04 LTS focal	Not affected
	18.04 LTS bionic	Not affected
	16.04 LTS xenial	Not affected
	14.04 LTS trusty	Not affected
openssl1.0	24.10 oracular	Not in release
	24.04 LTS noble	Not in release
	23.10 mantic	Not in release
	23.04 lunar	Not in release
	22.10 kinetic	Not in release
	22.04 LTS jammy	Not in release
	20.04 LTS focal	Not in release
	18.04 LTS bionic	Not affected
	16.04 LTS xenial	Not in release
	14.04 LTS trusty	Not in release

Notes

mdeslaur

only affected OpenSSL 3.x

Severity score breakdown

Parameter	Value
Base score	5.3 · Medium
Attack vector	Network
Attack complexity	Low
Privileges required	None
User interaction	None
Scope	Unchanged
Confidentiality	None
Integrity impact	Low
Availability impact	None
Vector	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

References

Related Ubuntu Security Notices (USN)

USN-6450-1
OpenSSL vulnerabilities
24 October 2023

Cvss 3 Severity Score