CVE-2009-1891 Denial of service in n/a

What is CVE-2009-1891?

CVE-2009-1891 is a high-severity denial of service vulnerability in Apache Http Server, published on 10 Jul 2009. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

The mod_deflate module in Apache httpd 2.2.11 and earlier compresses large files until completion even after the associated network connection is closed, which allows remote attackers to cause a denial of service (CPU consumption).

Weakness: CWE-400

Which versions are affected by CVE-2009-1891?

It affects 9 products.

Products include Apache Http Server, Canonical Ubuntu Linux, Debian Debian Linux, Fedoraproject Fedora, Redhat Enterprise Linux Desktop, Redhat Enterprise Linux Eus and 3 more.

How do I fix CVE-2009-1891?

Upgrade to a fixed version.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2009-1891 being exploited?

There is no known exploitation of CVE-2009-1891 in the wild and no public exploit code.

Other vulnerabilities in Apache Http Server

• CVE-2021-42013 Apache HTTP Server Path Traversal Exploited Critical 9.8
• CVE-2024-38475 Apache HTTP Server Improper Escaping of Output Exploited Critical 9.1
• CVE-2021-40438 Apache HTTP Server-Side Request Forgery (SSRF) Exploited Critical 9.0
• CVE-2019-0211 Apache HTTP Server Privilege Escalation Exploited High 7.8
• CVE-2021-41773 Apache HTTP Server Path Traversal Exploited High 7.5

All Apache Http Server vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as DEBIAN-CVE-2009-1891, GHSA-hwvh-jv6j-6p3p.