Vulnerability · Published Jun 10, 2021 · Assigned by apache
CVE-2021-26690mod_session NULL pointer dereference
High 7.5
In plain English
A high-severity security flaw in Apache HTTP Server from Apache Software Foundation. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 65.1% (higher than 99.3% of all known vulnerabilities). Ready-made attack tooling exists: public proof-of-concept code. Fixed versions are available - upgrade the affected package.
Severity (CVSS NVD)7.5High
Exploit odds (30 days)65.1%top 0.7% of all CVEs
Exploited in the wildNo reportsnot in CISA KEV
Attack tooling1Public PoC
Official description
Apache HTTP Server versions 2.4.0 to 2.4.46 A specially crafted Cookie header handled by mod_session can cause a NULL pointer dereference and crash, leading to a possible Denial Of Service
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux:8 | mod_http2 | 1.15.7-3.module_el8.5.0+2609+b30d9eec | ALSA-2021:4257 |
| AlmaLinux:8 | mod_md | 1:2.0.8-8.module_el8.5.0+2609+b30d9eec | ALSA-2021:4257 |
| AlmaLinux:8 | mod_md | 1:2.0.8-8.module_el8.6.0+2872+fe0ff7aa | ALSA-2021:4257 |
| Alpine:v3.20 | apache2 | 2.4.48-r0 | ALPINE-CVE-2021-26690 |
| Alpine:v3.21 | apache2 | 2.4.48-r0 | ALPINE-CVE-2021-26690 |
| Alpine:v3.22 | apache2 | 2.4.48-r0 | ALPINE-CVE-2021-26690 |
| Alpine:v3.23 | apache2 | 2.4.48-r0 | ALPINE-CVE-2021-26690 |
| Alpine:v3.24 | apache2 | 2.4.48-r0 | ALPINE-CVE-2021-26690 |
| Debian:12 | apache2 | 2.4.46-6 | DEBIAN-CVE-2021-26690 |
| Debian:13 | apache2 | 2.4.46-6 | DEBIAN-CVE-2021-26690 |
| Debian:14 | apache2 | 2.4.46-6 | DEBIAN-CVE-2021-26690 |
| Rocky Linux:8 | httpd | 0:2.4.37-41.module+el8.5.0+695+1fa8055e | RLSA-2021:4257 |
| Rocky Linux:8 | mod_http2 | 0:1.15.7-3.module+el8.5.0+695+1fa8055e | RLSA-2021:4257 |
| Rocky Linux:8 | mod_http2 | 0:1.15.7-3.module+el8.4.0+553+7a69454b | RLSA-2021:4257 |
| Rocky Linux:8 | mod_md | 1:2.0.8-8.module+el8.4.0+553+7a69454b | RLSA-2021:4257 |
| Rocky Linux:8 | mod_md | 1:2.0.8-8.module+el8.5.0+695+1fa8055e | RLSA-2021:4257 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Apache Software Foundation | Apache HTTP Server | 2.4.462.4.432.4.412.4.392.4.382.4.372.4.352.4.34 |
References
- http://httpd.apache.org/security/vulnerabilities_24.html x_refsource_MISC
- https://lists.apache.org/thread.html/re026d3da9d7824bd93b9f871c0fdda978d960c7e62d8c43cba8d0bf3%40%3Ccvs.httpd.apache.org%3E x_refsource_MISC
- [httpd-announce] 20210609 CVE-2021-26690: mod_session NULL pointer dereference mailing-list, x_refsource_MLIST
- [httpd-dev] 20210610 Re: svn commit: r1890598 - in /httpd/site/trunk/content/security/json: CVE-2019-17567.json CVE-2020-13938.json CVE-2020-13950.json CVE-2020-35452.json CVE-2021-26690.json CVE-2021-26691.json CVE-2021-30641.json CVE-2021-31618.json mailing-list, x_refsource_MLIST
- [oss-security] 20210609 CVE-2021-26690: Apache httpd: mod_session NULL pointer dereference mailing-list, x_refsource_MLIST
- [debian-lts-announce] 20210709 [SECURITY] [DLA 2706-1] apache2 security update mailing-list, x_refsource_MLIST
- DSA-4937 vendor-advisory, x_refsource_DEBIAN
- GLSA-202107-38 vendor-advisory, x_refsource_GENTOO
- FEDORA-2021-dce7e7738e vendor-advisory, x_refsource_FEDORA
- FEDORA-2021-e3f6dd670d vendor-advisory, x_refsource_FEDORA
- https://www.oracle.com/security-alerts/cpuoct2021.html x_refsource_MISC
- https://security.netapp.com/advisory/ntap-20210702-0001/ x_refsource_CONFIRM