CVE-2018-17281· NVD / CVE Program· CNA mitre

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

Noroxi assessment

Priority: Plan (action score 46/100)

The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
Probability of exploitation in the next 30 days: 52.4% (FIRST EPSS); higher than 98.9% of all records.
Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
Fixed version: asterisk (Debian:14) 1:13.23.1~dfsg-1; asterisk (Debian:8) 1:11.13.1~dfsg-2+deb8u6; asterisk (Debian:9) 1:13.14.1~dfsg-2+deb9u4.

Add it to your regular patch cycle. Upgrade to asterisk (Debian:14) 1:13.23.1~dfsg-1; asterisk (Debian:8) 1:11.13.1~dfsg-2+deb8u6; asterisk (Debian:9) 1:13.14.1~dfsg-2+deb9u4 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

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.

HighCVSS 7.5 · v3.0—No exploit Fix available

Published: Sep 24, 2018
Updated: Jun 16, 2026
EPSS: 52.4% · 98th percentile
CWE: CWE-400

Report tools

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Action score

Plan

Add it to your regular patch cycle.

CVSS: 30 / 40 · 7.5 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 16 / 30 · 52.4%

Get told when this record changes

Not in KEV: no record of exploitation in the wild
No public exploit code on record
A fix has been released

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

Vendor	Product	CPE
digium	asterisk	cpe:2.3:a:digium:asterisk
digium	certified asterisk	cpe:2.3:a:digium:certified_asterisk
debian	debian linux	cpe:2.3:o:debian:debian_linux

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

debian debian linux8.0
debian debian linux9.0
digium asterisk15.0.0 and later · up to 15.6.0 inclusive
digium asterisk13.0.0 and later · up to 13.23.0 inclusive
digium asterisk14.0.0 and later · up to 14.7.7 inclusive
digium certified asterisk11.6
digium certified asterisk13.1
digium certified asterisk13.13
digium certified asterisk13.21
digium certified asterisk13.8

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

Ecosystem	Package	Affected range	Fix
Debian:14	asterisk	before 1:13.23.1~dfsg-1	1:13.23.1~dfsg-1
Debian:8	asterisk	before 1:11.13.1~dfsg-2+deb8u6	1:11.13.1~dfsg-2+deb8u6
Debian:9	asterisk	before 1:13.14.1~dfsg-2+deb9u4	1:13.14.1~dfsg-2+deb9u4

Same product

digium: all records

Other highest-scoring records for the same primary product.

CVE-2006-5444Integer overflow in the get_input function in the Skinny channel driver (chan_skinny.c) in Asterisk 1.0.x before 1.0.12 and 1.2.x before 1.2
56Plan
CVE-2017-17850An issue was discovered in Asterisk 13.18.4 and older, 14.7.4 and older, 15.1.4 and older, and 13.18-cert1 and older.
53Plan
CVE-2019-18610An issue was discovered in manager.c in Sangoma Asterisk through 13.x, 16.x, 17.x and Certified Asterisk 13.21 through 13.21-cert4.
50Plan

Published before and after this one in the same product

← EarlierCVE-2018-7287Feb 21, 2018 · An issue was discovered in res_http_websocket.c in Asterisk 15.x through 15.2.1.
26Monitor
← EarlierCVE-2018-12227Jun 12, 2018 · An issue was discovered in Asterisk Open Source 13.x before 13.21.1, 14.x before 14.7.7, and 15.x before 15.4.1 and Certified Asterisk 13.18
22Monitor
Later →CVE-2018-19278Nov 14, 2018 · Buffer overflow in DNS SRV and NAPTR lookups in Digium Asterisk 15.x before 15.6.2 and 16.x before 16.0.1 allows remote attackers to crash A
31Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / package	Fixed version	Source
debian:asterisk	1:13.23.1~dfsg-1 · Debian:14	Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days-1% in 7 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

Anyone who can reach it over the internet can trigger it.
No account or password is required.
No user action is required.
No special conditions are required; it is repeatable.

If successful

Confidentiality: none
Integrity: none
Availability: high · the service can be disrupted

Attack vector: Network
Attack complexity: Low
Privileges required: None
User interaction: None
Scope: Unchanged
Confidentiality impact: None
Integrity impact: None
Availability impact: High

Weakness class (CWE)

CWE-400 · Uncontrolled Resource Consumption

CVSS vector

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

nvd-primary

Root cause

Code that parses nested structures sets no depth or size limit. A small input can turn into a disproportionate processing load.

The bug in code

The whole CWE-400 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

1function expand(node) {
2  return node.children.map(expand);
3}

Fixed

1const MAX_DEPTH = 32;
2function expand(node, depth = 0) {
3  if (depth > MAX_DEPTH) throw new Error("too deep");
4  return node.children.map((c) => expand(c, depth + 1));
5}

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

Attack patterns (CAPEC)

ATT&CK techniques

Endpoint Denial of ServiceT1499

Change log

Fix✗ → ✓Sep 28, 2026, 10:48 PM UTC

For records you follow, these changes also arrive as notifications. →

References

seclists.org/bugtraq/2018/Sep/53

Show all references (9 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records