CVE-2009-3622

WordPress Core <= 2.8.4 - Denial of Service

2009-10-20 00:00

Strategic Overview

Status: Patched in 2.8.5
Affected Core: WordPress 2.8
Affected Version: <= 2.8.4
CVSS: 6.5Medium
Weakness type: CWE-400 · Uncontrolled Resource Consumption
CVE: CVE-2009-3622

At a glance

CVE-2009-3622 is a medium-severity Uncontrolled Resource Consumption vulnerability in the WordPress 2.8 WordPress release line, affecting <= 2.8.4. It carries a CVSS score of 6.5 (reachable over the network; low attack complexity; high availability impact). The issue is fixed in version 2.8.5; sites on affected versions should update now. Disclosed October 2009.

Vulnerability Overview

Algorithmic complexity vulnerability in wp-trackback.php in WordPress before 2.8.5 allows remote attackers to cause a denial of service (CPU consumption and server hang) via a long title parameter in conjunction with a charset parameter composed of many comma-separated "UTF-8" substrings, related to the mb_convert_encoding function in PHP.

Technical Analysis

The vector marks this flaw as remotely reachable over the network, with low attack complexity — no special timing or configuration is needed, and no interaction from a victim user. A successful exploit has high impact on availability.

CWE-400: Uncontrolled Resource Consumption

WordPress 2.8 <= 2.8.4 carries this weakness at UTF-8, and reaching it takes a caller who can reach the endpoint. Uncontrolled resource consumption means a request can make the server do an amount of work it never bounds, because the size or repetition of the job is taken from the request rather than capped by the code.

A single caller can hold PHP workers, database connections or disk open long enough to slow the site for everyone, without needing any account or any other flaw. For WordPress 2.8 the fix is 2.8.5: builds <= 2.8.4 are affected, anything from 2.8.5 onward is not.

Remediation

Update to version 2.8.5, or a newer patched version

How does WordSec protect against this?

The attempt arrives as an ordinary request to WordPress 2.8: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: updating to 2.8.5 is the step that ends it.

Firewall
Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2009-3622 https://www.wordfence.com/threat-intel/vulnerabilities/id/81bf9a8d-fc70-45d9-a352-4a5bfb2c43f4 https://nvd.nist.gov/vuln/detail/CVE-2009-3622

Related records

Same weakness class

Other vulnerabilities in WordPress 2.8

CVSS Vector

6.5

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Base

Attack VectorNetwork
Attack ComplexityLow
Privileges RequiredLow
User InteractionNone
ScopeUnchanged
ConfidentialityNone
IntegrityNone
AvailabilityHigh

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