CVE-2021-23841

CVE Details

Release Date:

2021-02-16

Description

The OpenSSL public API function X509_issuer_and_serial_hash() attempts to create a unique hash value based on the issuer and serial number data contained within an X509 certificate. However it fails to correctly handle any errors that may occur while parsing the issuer field (which might occur if the issuer field is maliciously constructed). This may subsequently result in a NULL pointer deref and a crash leading to a potential denial of service attack. The function X509_issuer_and_serial_hash() is never directly called by OpenSSL itself so applications are only vulnerable if they use this function directly and they use it on certificates that may have been obtained from untrusted sources. OpenSSL versions 1.1.1i and below are affected by this issue. Users of these versions should upgrade to OpenSSL 1.1.1j. OpenSSL versions 1.0.2x and below are affected by this issue. However OpenSSL 1.0.2 is out of support and no longer receiving public updates. Premium support customers of OpenSSL 1.0.2 should upgrade to 1.0.2y. Other users should upgrade to 1.1.1j. Fixed in OpenSSL 1.1.1j (Affected 1.1.1-1.1.1i). Fixed in OpenSSL 1.0.2y (Affected 1.0.2-1.0.2x).

See more information about CVE-2021-23841 from MITRE CVE dictionary and NIST NVD

CVSS v3.0 metrics

NOTE: The following CVSS v3.0 metrics and score provided are preliminary and subject to review.

Base Score:	5.9	Base Metrics:	AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
Access Vector:	Network	Attack Complexity:	High
Privileges Required:	None	User Interaction:	None
Scope:	Unchanged	Confidentiality Impact:	None
Integrity Impact:	None	Availability Impact:	High

Errata information

Platform	Errata	Release Date
Oracle Linux version 7 (openssl)	ELSA-2021-3798	2021-10-13
Oracle Linux version 7 (openssl)	ELSA-2021-9478	2021-10-13
Oracle Linux version 7 (openssl)	ELSA-2021-9528	2021-10-29
Oracle Linux version 8 (openssl)	ELSA-2021-4424	2021-11-16
Oracle Linux version 8 (openssl)	ELSA-2021-9561	2021-11-23

This page is generated automatically and has not been checked for errors or omissions. For clarification or corrections please contact the Oracle Linux ULN team