What is CVE-2018-17281?

CVE-2018-17281 is a high-severity vulnerability in Digium Asterisk, classified under Uncontrolled Resource Consumption. CVSS score: 7.5/10. Published 2018-09-24.

How severe is CVE-2018-17281?

High severity. CVSS v3 base score is 7.5 out of 10.

Resource exhaustion in Digium Asterisk

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.

Vulnerability class: DoS (Denial of Service)

Published 2018-09-24 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.524 (99.0th percentile), scored 2026-10-19.

High probability of exploitation in the next 30 days — patch promptly. 99th percentile — 99.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.534 · newest: 0.524 · change: -0.009

Affected products

Digium Asterisk
Digium Certified Asterisk — versions 11.6, 13.1, 13.8
Debian Linux — versions 8.0, 9.0

Weakness classification (CWE)

CWE-400 — Uncontrolled Resource Consumption

References

www.securitytracker.com/id/1041694 (VDB Entry, Third Party Advisory, vdb-entry)
seclists.org/fulldisclosure/2018/Sep/31 (mailing-list, Patch, Mailing List, Third Party Advisory)
packetstormsecurity.com/files/149453/Asterisk-Project-Security-Advisory-AST-201… (VDB Entry, Third Party Advisory)
www.debian.org/security/2018/dsa-4320 (vendor-advisory, Third Party Advisory)
seclists.org/bugtraq/2018/Sep/53 (mailing-list, Patch, Mailing List, Third Party Advisory)
issues.asterisk.org/jira/browse/ASTERISK-28013 (Third Party Advisory, Issue Tracking)
lists.debian.org/debian-lts-announce/2018/09/msg00034.html (mailing-list, Mailing List, Third Party Advisory)
security.gentoo.org/glsa/201811-11 (vendor-advisory, Third Party Advisory)
www.securityfocus.com/bid/105389 (VDB Entry, Third Party Advisory, vdb-entry)
downloads.asterisk.org/pub/security/AST-2018-009.html (Patch, Vendor Advisory)

Frequently asked questions

What is CVE-2018-17281?: CVE-2018-17281 is a high-severity vulnerability in Digium Asterisk, classified under Uncontrolled Resource Consumption. CVSS score: 7.5/10. Published 2018-09-24.
How severe is CVE-2018-17281?: High severity. CVSS v3 base score is 7.5 out of 10.