Vulnerability · Published Oct 5, 2021 · Assigned by apache
CVE-2021-41524null pointer dereference in h2 fuzzing
High 7.5
In plain English
A high-severity null pointer dereference 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 25.8% (higher than 98% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Severity (CVSS NVD)7.5High
Exploit odds (30 days)25.8%top 2.0% of all CVEs
Exploited in the wildNo reportsnot in CISA KEV
Attack toolingNoneno public tooling known
Official description
While fuzzing the 2.4.49 httpd, a new null pointer dereference was detected during HTTP/2 request processing, allowing an external source to DoS the server. This requires a specially crafted request. The vulnerability was recently introduced in version 2.4.49. No exploit is known to the project.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine:v3.20 | apache2 | 2.4.50-r0 | ALPINE-CVE-2021-41524 |
| Alpine:v3.21 | apache2 | 2.4.50-r0 | ALPINE-CVE-2021-41524 |
| Alpine:v3.22 | apache2 | 2.4.50-r0 | ALPINE-CVE-2021-41524 |
| Alpine:v3.23 | apache2 | 2.4.50-r0 | ALPINE-CVE-2021-41524 |
| Alpine:v3.24 | apache2 | 2.4.50-r0 | ALPINE-CVE-2021-41524 |
| Debian:12 | apache2 | 2.4.50-1 | DEBIAN-CVE-2021-41524 |
| Debian:13 | apache2 | 2.4.50-1 | DEBIAN-CVE-2021-41524 |
| Debian:14 | apache2 | 2.4.50-1 | DEBIAN-CVE-2021-41524 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Apache Software Foundation | Apache HTTP Server | 2.4.49 |
Weakness: CWE-476
References
- https://httpd.apache.org/security/vulnerabilities_24.html x_refsource_MISC
- [oss-security] 20211005 CVE-2021-41524: Apache HTTP Server: null pointer dereference in h2 fuzzing mailing-list, x_refsource_MLIST
- FEDORA-2021-5d2d4b6ac5 vendor-advisory, x_refsource_FEDORA
- 20211007 Apache HTTP Server Vulnerabilties: October 2021 vendor-advisory, x_refsource_CISCO
- FEDORA-2021-f94985afca vendor-advisory, x_refsource_FEDORA
- https://www.oracle.com/security-alerts/cpujan2022.html x_refsource_MISC
- https://security.netapp.com/advisory/ntap-20211029-0009/ x_refsource_CONFIRM
- GLSA-202208-20 vendor-advisory, x_refsource_GENTOO