NULL Pointer Dereference Affecting openssl package, versions <1:1.1.1k-4.el8


Severity

Recommended
0.0
medium
0
10

Based on Red Hat Enterprise Linux security rating.

Threat Intelligence

EPSS
0.42% (75th percentile)

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  • Snyk IDSNYK-RHEL8-OPENSSL-4192142
  • published26 Jul 2021
  • disclosed16 Feb 2021

Introduced: 16 Feb 2021

CVE-2021-23841  (opens in a new tab)
CWE-476  (opens in a new tab)

How to fix?

Upgrade RHEL:8 openssl to version 1:1.1.1k-4.el8 or higher.
This issue was patched in RHSA-2021:4424.

NVD Description

Note: Versions mentioned in the description apply only to the upstream openssl package and not the openssl package as distributed by RHEL. See How to fix? for RHEL:8 relevant fixed versions and status.

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

CVSS Scores

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