CVE-2021-26690: mod_session NULL pointer dereference

Published Jun 1, 2021
·
Updated

A NULL pointer dereference was found in Apache httpd modsession. The highest threat from this vulnerability is to system availability.

Other sources

Apache HTTP Server versions 2.4.0 to 2.4.46 A specially crafted Cookie header handled by modsession can cause a NULL pointer dereference and crash, leading to a possible Denial Of Service

In Apache httpd before 2.4.48 modsession has a NULL pointer dereference in parser.

References:

https://github.com/apache/httpd/commit/67bd9bfe6c38831e14fe7122f1d84391472498f8

Red Hat

Affected Software

27 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/httpd<2.4.47
2.4.47
Apache HTTP Server>=2.4.0<=2.4.46
Debian Debian Linux=9.0
Debian Debian Linux=10.0
Fedoraproject Fedora=34
Fedoraproject Fedora=35
Oracle Enterprise Manager Ops Center=12.4.0.0
Oracle Instantis Enterprisetrack=17.1
Oracle Instantis Enterprisetrack=17.2
Oracle Instantis Enterprisetrack=17.3
Oracle ZFS Storage Appliance Kit=8.8

Remediation

Information

Only configurations which use the "SessionEnv" directive (which is not widely used) are vulnerable to this flaw. SessionEnv is not enabled in default configuration of httpd package shipped with Red Hat Products.

Event History

Jun 1, 2021
Data Sourced
via Red Hat·06:34 PM
DescriptionSeverityAffected Software
Jun 4, 2021
CVE Published
12:00 AM
Jun 10, 2021
CVE Published
via MITRE·07:10 AM
Data Sourced
via MITRE·07:10 AM
DescriptionWeakness

Parent advisories

This vulnerability appears in the following advisories.

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Frequently Asked Questions

1

What is CVE-2021-26690?

CVE-2021-26690 is a vulnerability in Apache httpd mod_session that can cause a NULL pointer dereference and crash, leading to a possible Denial of Service (DoS).

2

Which versions of Apache HTTP Server are affected by CVE-2021-26690?

Apache HTTP Server versions 2.4.0 to 2.4.46 are affected by CVE-2021-26690.

3

What is the severity of CVE-2021-26690?

The severity of CVE-2021-26690 is high, with a CVSS score of 7.5.

4

How can CVE-2021-26690 be fixed?

To fix CVE-2021-26690, upgrade to Apache HTTP Server version 2.4.47 or higher.

5

Are there any references for CVE-2021-26690?

Yes, you can find references for CVE-2021-26690 at the following links: [GitHub Commit](https://github.com/apache/httpd/commit/67bd9bfe6c38831e14fe7122f1d84391472498f8), [Red Hat Support](https://access.redhat.com/support/policy/updates/jboss_notes), [Red Hat Bugzilla](https://bugzilla.redhat.com/show_bug.cgi/show_bug.cgi?id=1968308).

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