Resource exhaustion in Apache HTTP Server

CVE-2009-1891

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).

Vulnerability class: DoS (Denial of Service)

Published · last modified .

CVSS v2 metric

CVSS v2 base score 7.1 (High). Vector: AV:N/AC:M/Au:N/C:N/I:N/A:C. This CVE predates CVSS v3 and has no v3 score from NVD.

EPSS exploit prediction

EPSS: 0.171 (97.0th percentile), scored .

Moderate probability of exploitation in the next 30 days — watch for active exploitation reports. 97th percentile — 97.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2009-1891: held from 0.171 to 0.171.

EPSS over last 30 days · oldest: 0.171 · newest: 0.171 · change: 0.000

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2009-1891?
CVE-2009-1891 is a vulnerability in Apache HTTP Server, classified under Uncontrolled Resource Consumption. Published 2009-07-10.
Is CVE-2009-1891 known to be exploited?
22 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.