CVE-2021-23841 Information

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).

CVSS Vector

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

Reference

https://www.openssl.org/news/secadv/20210216.txt https://git.openssl.org/gitweb/?p=openssl.git;a=commitdiff;h=8252ee4d90f3f2004d3d0aeeed003ad49c9a7807 https://git.openssl.org/gitweb/?p=openssl.git;a=commitdiff;h=122a19ab48091c657f7cb1fb3af9fc07bd557bbf https://www.debian.org/security/2021/dsa-4855 https://security.netapp.com/advisory/ntap-20210219-0009/ https://www.tenable.com/security/tns-2021-03 https://security.gentoo.org/glsa/202103-03 https://www.tenable.com/security/tns-2021-09 https://security.netapp.com/advisory/ntap-20210513-0002/ https://support.apple.com/kb/HT212529 https://support.apple.com/kb/HT212528 https://support.apple.com/kb/HT212534 http://seclists.org/fulldisclosure/2021/May/68 http://seclists.org/fulldisclosure/2021/May/67 http://seclists.org/fulldisclosure/2021/May/70 https://www.oracle.com/security-alerts/cpuApr2021.html https://kb.pulsesecure.net/articles/Pulse_Security_Advisories/SA44846 https://www.oracle.com//security-alerts/cpujul2021.html https://www.oracle.com/security-alerts/cpuoct2021.html https://www.oracle.com/security-alerts/cpuapr2022.html

Attack Complexity

HIGH

Privileges Required

NONE

User Interaction Required

NONE

Scope

NONE

Confidentiality Impact

UNCHANGED

Integrity Impact

NONE

Availability Impact

NONE

Base Score

HIGH

Base Severity

5.9