CVE-2021-23841

medium

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).

References

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

Details

Source: MITRE

Published: 2021-02-16

Updated: 2022-05-12

Risk Information

CVSS v2

Base Score: 4.3

Vector: AV:N/AC:M/Au:N/C:N/I:N/A:P

Impact Score: 2.9

Exploitability Score: 8.6

Severity: MEDIUM

CVSS v3

Base Score: 5.9

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

Impact Score: 3.6

Exploitability Score: 2.2

Severity: MEDIUM