CVE-2018-17281

There is a stack consumption vulnerability in the res_http_websocket.so module of Asterisk through 13.23.0, 14.7.x through 14.7.7, and 15.x through 15.6.0 and Certified Asterisk through 13.21-cert2. It allows an attacker to crash Asterisk via a specially crafted HTTP request to upgrade the connection to a websocket.

Weakness

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

Affected Software

Name	Vendor	Start Version	End Version
Asterisk	Digium	13.0.0 (including)	13.23.0 (including)
Asterisk	Digium	14.0.0 (including)	14.7.7 (including)
Asterisk	Digium	15.0.0 (including)	15.6.0 (including)
Asterisk	Ubuntu	bionic	*
Asterisk	Ubuntu	cosmic	*
Asterisk	Ubuntu	esm-apps/bionic	*
Asterisk	Ubuntu	esm-apps/xenial	*
Asterisk	Ubuntu	trusty	*
Asterisk	Ubuntu	upstream	*
Asterisk	Ubuntu	xenial	*

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-2018-17281
CWE	https://cwe.mitre.org/data/definitions/400.html

Uncontrolled Resource Consumption

Weakness

Affected Software

Potential Mitigations

References

CVE-2018-17281

Uncontrolled Resource Consumption

Weakness

Affected Software

Potential Mitigations

Related Attack Patterns

References