Vulnerability identifier: #VU10698

Vulnerability risk: Low

CVSSv3.1: 4.8 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L/E:P/RL:O/RC:C]

CVE-ID: CVE-2018-7284

CWE-ID: CWE-20

Exploitation vector: Network

Exploit availability: Yes

Vulnerable software:
Asterisk Open Source
Server applications / Conferencing, Collaboration and VoIP solutions

Vendor: Digium (Linux Support Services)

Description
The vulnerability allows a remote attacker to cause DoS condition on the target system.

The weakness exists due to improper input validation. A remote attacker can send a SUBSCRIBE request with specially crafted Accept headersб trigger a flaw in the 'res_pjsip_pubsub' module and cause the target service to crash.

Mitigation
Update to version 13.19.2, 14.7.6, 15.2.2.

Vulnerable software versions

Asterisk Open Source: 15.0.0 - 15.2.1, 13.0.0 - 13.18.5, 14.0 - 14.7.5

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External links
http://downloads.asterisk.org/pub/security/AST-2018-004.html

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability. However, proof of concept for this vulnerability is available.