CVE-2009-1890

The stream_reqbody_cl function in mod_proxy_http.c in the mod_proxy module in the Apache HTTP Server before 2.3.3, when a reverse proxy is configured, does not properly handle an amount of streamed data that exceeds the Content-Length value, which allows remote attackers to cause a denial of service (CPU consumption) via crafted requests.

Weakness

The product does not properly control the allocation and maintenance of a limited resource.

Affected Software

Name	Vendor	Start Version	End Version
Http_server	Apache	2.2.0 (including)	2.2.12 (excluding)
JBEWS 1.0 for RHEL 4	RedHat	httpd22-0:2.2.10-23.1.ep5.el4	*
Red Hat Enterprise Linux 5	RedHat	httpd-0:2.2.3-22.el5_3.2	*
Red Hat JBoss Enterprise Web Server 1 for RHEL 5	RedHat	httpd-0:2.2.10-10.ep5.el5	*
Apache2	Ubuntu	hardy	*
Apache2	Ubuntu	intrepid	*
Apache2	Ubuntu	jaunty	*
Apache2	Ubuntu	upstream	*

Potential Mitigations

Mitigation of resource exhaustion attacks requires that the target system either:
The first of these solutions is an issue in itself though, since it may allow attackers to prevent the use of the system by a particular valid user. If the attacker impersonates the valid user, they may be able to prevent the user from accessing the server in question.
The second solution is simply difficult to effectively institute – and even when properly done, it does not provide a full solution. It simply makes the attack require more resources on the part of the attacker.

NVD	https://nvd.nist.gov/vuln/detail/CVE-2009-1890
CWE	https://cwe.mitre.org/data/definitions/400.html

Uncontrolled Resource Consumption

Weakness

Affected Software

Potential Mitigations

References

CVE-2009-1890

Uncontrolled Resource Consumption

Weakness

Affected Software

Potential Mitigations

Related Attack Patterns

References