CVE-2021-23841: Null pointer deref in X509_issuer_and_serial_hash()

Q: What is CVE-2021-23841?

CVE-2021-23841 is a vulnerability that involves a null pointer dereference in the OpenSSL public API function X509_issuer_and_serial_hash().

Q: What is the severity of CVE-2021-23841?

The severity of CVE-2021-23841 is medium with a CVSS score of 5.9.

Q: How does CVE-2021-23841 affect Safari?

CVE-2021-23841 may affect Safari users, but it is recommended to refer to Apple's support page for specific information and remedies.

Q: How do I fix CVE-2021-23841 on Red Hat products?

To fix CVE-2021-23841 on Red Hat products, update the affected packages to the specified versions provided by Red Hat.

Q: What are the references for CVE-2021-23841?

The references for CVE-2021-23841 can be found at the following URLs: 1. [Apple Support - HT212529](https://support.apple.com/en-us/HT212529) 2. [Apple Support - HT212534](https://support.apple.com/en-us/HT212534) 3. [Apple Support - HT212528](https://support.apple.com/en-us/HT212528)

Published Feb 16, 2021

Updated

Last updated 24 July 2024

Other sources

Null pointer deref in X509issuerandserialhash()

— Microsoft

OpenSSL is vulnerable to a denial of service, caused by a NULL pointer dereference in the X509issuerandserialhash() function. By parsing the issuer field, an attacker could exploit this vulnerability to cause the application to crash.

— IBM

The OpenSSL public API function X509issuerandserialhash() 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.

WebRTC. A null pointer dereference was addressed with improved input validation.

Credit

Tavis Ormandy(Google)

Affected Software

93 affected componentsFixes available

redhat/jbcs-httpd24-apr<0:1.6.3-107.el8

0:1.6.3-107.el8

redhat/jbcs-httpd24-apr-util<0:1.6.1-84.el8

0:1.6.1-84.el8

redhat/jbcs-httpd24-curl<0:7.78.0-2.el8

0:7.78.0-2.el8

redhat/jbcs-httpd24-httpd<0:2.4.37-78.el8

0:2.4.37-78.el8

redhat/jbcs-httpd24-nghttp2<0:1.39.2-39.el8

0:1.39.2-39.el8

redhat/jbcs-httpd24-openssl<1:1.1.1g-8.el8

1:1.1.1g-8.el8

redhat/jbcs-httpd24-openssl-chil<0:1.0.0-7.el8

0:1.0.0-7.el8

redhat/jbcs-httpd24-openssl-pkcs11<0:0.4.10-22.el8

0:0.4.10-22.el8

redhat/jbcs-httpd24-apr<0:1.6.3-107.jbcs.el7

0:1.6.3-107.jbcs.el7

redhat/jbcs-httpd24-apr-util<0:1.6.1-84.jbcs.el7

0:1.6.1-84.jbcs.el7

redhat/jbcs-httpd24-curl<0:7.78.0-2.jbcs.el7

0:7.78.0-2.jbcs.el7

redhat/jbcs-httpd24-httpd<0:2.4.37-78.jbcs.el7

0:2.4.37-78.jbcs.el7

redhat/jbcs-httpd24-nghttp2<0:1.39.2-39.jbcs.el7

0:1.39.2-39.jbcs.el7

redhat/jbcs-httpd24-openssl<1:1.1.1g-8.jbcs.el7

1:1.1.1g-8.jbcs.el7

redhat/jbcs-httpd24-openssl-chil<0:1.0.0-7.jbcs.el7

0:1.0.0-7.jbcs.el7

redhat/jbcs-httpd24-openssl-pkcs11<0:0.4.10-22.jbcs.el7

0:0.4.10-22.jbcs.el7

redhat/openssl<1:1.0.2k-22.el7_9

1:1.0.2k-22.el7_9

redhat/edk2<0:20210527gite1999b264f1f-3.el8

0:20210527gite1999b264f1f-3.el8

redhat/openssl<1:1.1.1k-4.el8

1:1.1.1k-4.el8

redhat/jws5-tomcat<0:9.0.50-3.redhat_00004.1.el7

0:9.0.50-3.redhat_00004.1.el7

redhat/jws5-tomcat-native<0:1.2.30-3.redhat_3.el7

0:1.2.30-3.redhat_3.el7

redhat/jws5-tomcat-vault<0:1.1.8-4.Final_redhat_00004.1.el7

0:1.1.8-4.Final_redhat_00004.1.el7

redhat/jws5-tomcat<0:9.0.50-3.redhat_00004.1.el8

0:9.0.50-3.redhat_00004.1.el8

redhat/jws5-tomcat-native<0:1.2.30-3.redhat_3.el8

0:1.2.30-3.redhat_3.el8

redhat/jws5-tomcat-vault<0:1.1.8-4.Final_redhat_00004.1.el8

0:1.1.8-4.Final_redhat_00004.1.el8

Apple macOS Big Sur<11.4

11.4

IBM Security Verify Bridge<=All

Apple Safari<14.1.1

14.1.1

Apple iOS<14.6

14.6

Apple iPadOS<14.6

14.6

OpenSSL OpenSSL>=1.0.2<1.0.2y

OpenSSL OpenSSL>=1.1.1<1.1.1j

Debian Debian Linux=10.0

Tenable Nessus Network Monitor=5.11.0

Tenable Nessus Network Monitor=5.11.1

Tenable Nessus Network Monitor=5.12.0

Tenable Nessus Network Monitor=5.12.1

Tenable Nessus Network Monitor=5.13.0

Tenable Tenable.Sc>=5.13.0<=5.17.0

Apple Safari<14.1.1

Apple iPadOS<14.6

Apple iPhone OS<14.6

Apple macOS>=11.1<11.4

NetApp OnCommand Insight

NetApp OnCommand Workflow Automation

NetApp Snapcenter

Oracle Business Intelligence=5.5.0.0.0

Oracle Business Intelligence=5.9.0.0.0

Oracle Business Intelligence=12.2.1.3.0

Oracle Business Intelligence=12.2.1.4.0

Oracle Communications Cloud Native Core Policy=1.15.0

Oracle Enterprise Manager For Storage Management=13.4.0.0

Oracle Enterprise Manager Ops Center=12.4.0.0

Oracle Essbase=21.2

Oracle GraalVM=19.3.5

Oracle GraalVM=20.3.1.2

Oracle GraalVM=21.0.0.2

Oracle Jd Edwards World Security=a9.4

Oracle MySQL Enterprise Monitor<8.0.23

Oracle MySQL Server<5.7.33

Oracle MySQL Server>=8.0.15<8.0.23

Oracle PeopleSoft Enterprise PeopleTools=8.57

Oracle PeopleSoft Enterprise PeopleTools=8.58

Oracle PeopleSoft Enterprise PeopleTools=8.59

Oracle ZFS Storage Appliance Kit=8.8

Siemens Sinec Ins<1.0

Siemens Sinec Ins=1.0

Siemens Sinec Ins=1.0-sp1

Microsoft azl3 shim-unsigned-aarch64 15.8-5

Patch available

Microsoft azl3 shim-unsigned-x64 15.8-5

Patch available

redhat/openssl<1.1.1

1.1.1

redhat/openssl<1.0.2

1.0.2

debian/openssl

3.0.20-1~deb12u23.0.22-1~deb12u23.5.7-1~deb13u23.5.7-1~deb13u33.6.5-1