HOME VULNERABILITIESCVE-2023-49786

MEDIUM

CVE-2023-49786

CWE-703Published: December 14, 2023· Updated: Jun 17, 2026

5.9

CVSS v3.1

Official Description

Asterisk is an open source private branch exchange and telephony toolkit. In Asterisk prior to versions 18.20.1, 20.5.1, and 21.0.1; as well as certified-asterisk prior to 18.9-cert6; Asterisk is susceptible to a DoS due to a race condition in the hello handshake phase of the DTLS protocol when handling DTLS-SRTP for media setup. This attack can be done continuously, thus denying new DTLS-SRTP encrypted calls during the attack. Abuse of this vulnerability may lead to a massive Denial of Service on vulnerable Asterisk servers for calls that rely on DTLS-SRTP. Commit d7d7764cb07c8a1872804321302ef93bf62cba05 contains a fix, which is part of versions 18.20.1, 20.5.1, 21.0.1, amd 18.9-cert6.

Technical Analysis

CVE-2023-49786 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in availability disruption (denial of service), with a CVSS base score of 5.9.

CVSS v3.1 Vector Breakdown

Exploitability

Attack VectorNetwork

Attack ComplexityHigh

Privileges Req.None

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityNone

IntegrityNone

AvailabilityHigh

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected Vendors & Products

digium1 product(s)

asterisk

sangoma1 product(s)

certified asterisk

Source: NVD CPE · 5 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time

Offensive Security exploit database

GitHub PoC Search

Community PoC repositories

Rapid7 / Metasploit

Metasploit module search

Security advisories & exploits

Official NIST entry

CVE Program entry

External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

PATCHhttps://github.com/asterisk/asterisk/commit/d7d7764cb07c8a1872804321302ef93bf62cba05

PATCHhttps://github.com/asterisk/asterisk/commit/d7d7764cb07c8a1872804321302ef93bf62cba05

ADVISORYhttp://packetstormsecurity.com/files/176251/Asterisk-20.1.0-Denial-Of-Service.html

ADVISORYhttp://seclists.org/fulldisclosure/2023/Dec/24

ADVISORYhttps://github.com/asterisk/asterisk/security/advisories/GHSA-hxj9-xwr8-w8pq

ADVISORYhttp://packetstormsecurity.com/files/176251/Asterisk-20.1.0-Denial-Of-Service.html

ADVISORYhttp://seclists.org/fulldisclosure/2023/Dec/24

ADVISORYhttps://github.com/asterisk/asterisk/security/advisories/GHSA-hxj9-xwr8-w8pq

All References (14)

→

http://packetstormsecurity.com/files/176251/Asterisk-20.1.0-Denial-Of-Service.htmlExploit · Third Party Advisory · VDB Entry

→

http://seclists.org/fulldisclosure/2023/Dec/24Exploit · Mailing List · Third Party Advisory

→

http://www.openwall.com/lists/oss-security/2023/12/15/7Exploit · Mailing List

→

https://github.com/EnableSecurity/advisories/tree/master/ES2023-01-asterisk-dtls-hello-raceExploit

→

https://github.com/asterisk/asterisk/commit/d7d7764cb07c8a1872804321302ef93bf62cba05Patch

→

https://github.com/asterisk/asterisk/security/advisories/GHSA-hxj9-xwr8-w8pqExploit · Vendor Advisory

→

https://lists.debian.org/debian-lts-announce/2023/12/msg00019.html

→

http://packetstormsecurity.com/files/176251/Asterisk-20.1.0-Denial-Of-Service.htmlExploit · Third Party Advisory · VDB Entry

→

http://seclists.org/fulldisclosure/2023/Dec/24Exploit · Mailing List · Third Party Advisory

→

http://www.openwall.com/lists/oss-security/2023/12/15/7Exploit · Mailing List

→

https://github.com/EnableSecurity/advisories/tree/master/ES2023-01-asterisk-dtls-hello-raceExploit

→

https://github.com/asterisk/asterisk/commit/d7d7764cb07c8a1872804321302ef93bf62cba05Patch

→

https://github.com/asterisk/asterisk/security/advisories/GHSA-hxj9-xwr8-w8pqExploit · Vendor Advisory

→

https://lists.debian.org/debian-lts-announce/2023/12/msg00019.html

Quick Facts

CVE IDCVE-2023-49786

CVSS Score5.9 / 10

SeverityMEDIUM

WeaknessCWE-703

CISA KEVNo

Affected2 vendor(s)

PublishedDec 14, 2023

Related CVEs (CWE-703)

Recommended Actions

→Apply vendor patches immediately
→Monitor CVE-2023-49786 in threat intel feeds
→Review IDS/IPS signatures for exploitation attempts

Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.

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