Vulnerability Monitor

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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).

Security Impact Summary

CVE-2009-1891 is a security vulnerability that . Impacting 9 products from apache, from debian, from fedoraproject and 6 others, organizations running these solutions should prioritize assessment and patching.

Historical Context

Originally identified in 2009, this vulnerability predates many modern security frameworks and practices. The vulnerability landscape of that era was characterized by different threat models and less mature defense mechanisms compared to contemporary standards.

Published

2009-07-10T15:30:00.187

Last Modified

2026-04-23T00:35:47.467

Status

Modified

Source

[email protected]

Severity

CVSSv2: 7.1 (HIGH)

CVSSv2 Vector

AV:N/AC:M/Au:N/C:N/I:N/A:C

  • Access Vector: NETWORK
  • Access Complexity: MEDIUM
  • Authentication: NONE
  • Confidentiality Impact: NONE
  • Integrity Impact: NONE
  • Availability Impact: COMPLETE
Exploitability Score

8.6

Impact Score

6.9

Weaknesses
  • Type: Primary
    CWE-400
Affected Vendors & Products
Type Vendor Product Version/Range Vulnerable?
Application apache http_server < 2.0.64 Yes
Application apache http_server < 2.2.12 Yes
Operating System debian debian_linux 4.0 Yes
Operating System debian debian_linux 5.0 Yes
Operating System debian debian_linux 6.0 Yes
Operating System fedoraproject fedora 11 Yes
Operating System canonical ubuntu_linux 6.06 Yes
Operating System canonical ubuntu_linux 8.04 Yes
Operating System canonical ubuntu_linux 8.10 Yes
Operating System canonical ubuntu_linux 9.04 Yes
Operating System redhat enterprise_linux_desktop 5.0 Yes
Operating System redhat enterprise_linux_eus 5.3 Yes
Operating System redhat enterprise_linux_server 5.0 Yes
Operating System redhat enterprise_linux_server_aus 5.3 Yes
Operating System redhat enterprise_linux_workstation 5.0 Yes
References

How SecUtils Interprets This CVE

SecUtils normalizes and enriches National Vulnerability Database (NVD) records by standardizing vendor and product identifiers, aggregating vulnerability metadata from both NVD and MITRE sources, and providing structured context for security teams. For apache's affected products, we extract Common Platform Enumeration (CPE) data, Common Weakness Enumeration (CWE) classifications, CVSS severity metrics, and reference data to enable rapid vulnerability prioritization and asset correlation. This record contains no exploit code, proof-of-concept instructions, or attack methodologies—only defensive intelligence necessary for patch management, risk assessment, and security operations.