CVE-2021-26690: mod_session NULL pointer dereference
First published: Tue Jun 01 2021(Updated: )
A NULL pointer dereference was found in Apache httpd mod_session. The highest threat from this vulnerability is to system availability.
Credit: security@apache.org
| Affected Software | Affected Version | How to fix |
|---|---|---|
| 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 | =9.0 | |
| Debian | =10.0 | |
| Fedora | =34 | |
| 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 Sun ZFS Storage Appliance Kit | =8.8 |
Remedy
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.
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Reference Links
- https://www.cve.org/CVERecord?id=CVE-2021-26690 https://nvd.nist.gov/vuln/detail/CVE-2021-26690 https://httpd.apache.org/security/vulnerabilities_24.html
- https://bugzilla.redhat.com/show_bug.cgi?id=1966729
- https://access.redhat.com/errata/RHSA-2021:4614
- https://access.redhat.com/errata/RHSA-2021:4257
- https://access.redhat.com/errata/RHSA-2021:4613
- https://access.redhat.com/security/cve/cve-2021-26690
- http://httpd.apache.org/security/vulnerabilities_24.html
- http://www.openwall.com/lists/oss-security/2021/06/10/6
- https://lists.apache.org/thread.html/r7f2b70b621651548f4b6f027552f1dd91705d7111bb5d15cda0a68dd@%3Cdev.httpd.apache.org%3E
- https://lists.apache.org/thread.html/rae406c1d19c0dfd3103c96923dadac2af1cd0bad6905ab1ede153865@%3Cannounce.httpd.apache.org%3E
- https://lists.apache.org/thread.html/re026d3da9d7824bd93b9f871c0fdda978d960c7e62d8c43cba8d0bf3%40%3Ccvs.httpd.apache.org%3E
- https://lists.debian.org/debian-lts-announce/2021/07/msg00006.html
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/SPBR6WUYBJNACHKE65SPL7TJOHX7RHWD/
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/ZNCYSR3BXT36FFF4XTCPL3HDQK4VP45R/
- https://security.gentoo.org/glsa/202107-38
- https://security.netapp.com/advisory/ntap-20210702-0001/
- https://www.debian.org/security/2021/dsa-4937
- https://www.oracle.com/security-alerts/cpuoct2021.html
- https://github.com/apache/httpd/commit/67bd9bfe6c38831e14fe7122f1d84391472498f8
- https://access.redhat.com/support/policy/updates/jboss_notes
- https://bugzilla.redhat.com/show_bug.cgi/show_bug.cgi?id=1968308
- https://lists.apache.org/thread.html/rae406c1d19c0dfd3103c96923dadac2af1cd0bad6905ab1ede153865%40%3Cannounce.httpd.apache.org%3E
- https://lists.apache.org/thread.html/r7f2b70b621651548f4b6f027552f1dd91705d7111bb5d15cda0a68dd%40%3Cdev.httpd.apache.org%3E
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/SPBR6WUYBJNACHKE65SPL7TJOHX7RHWD/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZNCYSR3BXT36FFF4XTCPL3HDQK4VP45R/
Parent vulnerabilities
(Appears in the following advisories)
Frequently Asked Questions
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).
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.
What is the severity of CVE-2021-26690?
The severity of CVE-2021-26690 is high, with a CVSS score of 7.5.
How can CVE-2021-26690 be fixed?
To fix CVE-2021-26690, upgrade to Apache HTTP Server version 2.4.47 or higher.
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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