CVE-2023-49786 | Asterisk susceptible to Denial of Service via DTLS Hello packets during call initiation

Exp

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.

Published: 2023-12-14 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2023-49786 is rated Exploit Available (55.9/100): CVSS High severity, with low exploitation likelihood (EPSS 0.12%). 5 public exploit reference(s) are indexed (Exploit-DB). Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2023-49786

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗
— nvd_ref exploit_tag Exploit-DB ↗
— nvd_ref exploit_tag Exploit-DB ↗
— nvd_ref exploit_tag Exploit-DB ↗
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2023-49786

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2025-11-21 0.45% 0.12% -0.33%
2 2025-11-18 0.05% 0.45% +0.40%
3 2025-10-01 — 0.05% —

Full EPSS history (20 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2023-49786

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 3.6 [email protected]
5.9 3.1 MEDIUM
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 2.2 3.6 [email protected]

Weakness enumeration for CVE-2023-49786

OS Trackers for CVE-2023-49786

vendor priority summary link
alpine — CVE-2023-49786: 1 source package rows (asterisk); 72 state rows across 7 repos (3.17-main, 3.18-main, 3.19-main, 3.20-main, 3.21-main, 3.22-main, edge-main); fixed 7, open 65. https://security.alpinelinux.org/vuln/CVE-2023-49786
debian not yet assigned CVE-2023-49786 not yet assigned priority: Debian including 1 source packages (asterisk), 2 status rows across 2 suites (bullseye, sid): resolved 2. https://security-tracker.debian.org/tracker/CVE-2023-49786
gentoo high CVE-2023-49786: 1 GLSA(s) (202412-03), 1 atom(s) (net-misc/asterisk); latest impact high. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2023-49786
ubuntu medium CVE-2023-49786 medium priority: Ubuntu including 1 source packages (asterisk), 12 status rows across 12 suites (bionic, focal, jammy, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): needs-triage 7, ignored 5. https://ubuntu.com/security/CVE-2023-49786

Affected software / configurations for CVE-2023-49786

Vendor Product Version Raw CPE
digium asterisk < 18.20.1 cpe:2.3:a:digium:asterisk:*:*:*:*:*:*:*:*
digium asterisk >= 19.0.0, < 20.5.1 cpe:2.3:a:digium:asterisk:*:*:*:*:*:*:*:*
digium asterisk 21.0.0 cpe:2.3:a:digium:asterisk:21.0.0:*:*:*:*:*:*:*
sangoma certified_asterisk 13.13.0 cpe:2.3:a:sangoma:certified_asterisk:13.13.0:*:*:*:*:*:*:*
sangoma certified_asterisk 13.13.0 cpe:2.3:a:sangoma:certified_asterisk:13.13.0:cert1:*:*:*:*:*:*
sangoma certified_asterisk 13.13.0 cpe:2.3:a:sangoma:certified_asterisk:13.13.0:cert1-rc1:*:*:*:*:*:*
sangoma certified_asterisk 13.13.0 cpe:2.3:a:sangoma:certified_asterisk:13.13.0:cert1-rc2:*:*:*:*:*:*
sangoma certified_asterisk 13.13.0 cpe:2.3:a:sangoma:certified_asterisk:13.13.0:cert1-rc3:*:*:*:*:*:*
sangoma certified_asterisk 13.13.0 cpe:2.3:a:sangoma:certified_asterisk:13.13.0:cert1-rc4:*:*:*:*:*:*
sangoma certified_asterisk 13.13.0 cpe:2.3:a:sangoma:certified_asterisk:13.13.0:cert2:*:*:*:*:*:*
sangoma certified_asterisk 13.13.0 cpe:2.3:a:sangoma:certified_asterisk:13.13.0:cert3:*:*:*:*:*:*
sangoma certified_asterisk 13.13.0 cpe:2.3:a:sangoma:certified_asterisk:13.13.0:rc1:*:*:*:*:*:*
sangoma certified_asterisk 13.13.0 cpe:2.3:a:sangoma:certified_asterisk:13.13.0:rc2:*:*:*:*:*:*
sangoma certified_asterisk 16.8.0 cpe:2.3:a:sangoma:certified_asterisk:16.8.0:-:*:*:*:*:*:*
sangoma certified_asterisk 16.8.0 cpe:2.3:a:sangoma:certified_asterisk:16.8.0:cert1:*:*:*:*:*:*
sangoma certified_asterisk 16.8.0 cpe:2.3:a:sangoma:certified_asterisk:16.8.0:cert10:*:*:*:*:*:*
sangoma certified_asterisk 16.8.0 cpe:2.3:a:sangoma:certified_asterisk:16.8.0:cert11:*:*:*:*:*:*
sangoma certified_asterisk 16.8.0 cpe:2.3:a:sangoma:certified_asterisk:16.8.0:cert12:*:*:*:*:*:*
sangoma certified_asterisk 16.8.0 cpe:2.3:a:sangoma:certified_asterisk:16.8.0:cert2:*:*:*:*:*:*
sangoma certified_asterisk 16.8.0 cpe:2.3:a:sangoma:certified_asterisk:16.8.0:cert3:*:*:*:*:*:*
sangoma certified_asterisk 16.8.0 cpe:2.3:a:sangoma:certified_asterisk:16.8.0:cert4:*:*:*:*:*:*
sangoma certified_asterisk 16.8.0 cpe:2.3:a:sangoma:certified_asterisk:16.8.0:cert5:*:*:*:*:*:*
sangoma certified_asterisk 16.8.0 cpe:2.3:a:sangoma:certified_asterisk:16.8.0:cert6:*:*:*:*:*:*
sangoma certified_asterisk 16.8.0 cpe:2.3:a:sangoma:certified_asterisk:16.8.0:cert7:*:*:*:*:*:*
sangoma certified_asterisk 16.8.0 cpe:2.3:a:sangoma:certified_asterisk:16.8.0:cert8:*:*:*:*:*:*
sangoma certified_asterisk 16.8.0 cpe:2.3:a:sangoma:certified_asterisk:16.8.0:cert9:*:*:*:*:*:*
sangoma certified_asterisk 18.9 cpe:2.3:a:sangoma:certified_asterisk:18.9:cert1:*:*:*:*:*:*
sangoma certified_asterisk 18.9 cpe:2.3:a:sangoma:certified_asterisk:18.9:cert2:*:*:*:*:*:*
sangoma certified_asterisk 18.9 cpe:2.3:a:sangoma:certified_asterisk:18.9:cert3:*:*:*:*:*:*
sangoma certified_asterisk 18.9 cpe:2.3:a:sangoma:certified_asterisk:18.9:cert4:*:*:*:*:*:*
sangoma certified_asterisk 18.9 cpe:2.3:a:sangoma:certified_asterisk:18.9:cert5:*:*:*:*:*:*

References for CVE-2023-49786

cvelogic Threat Intelligence