Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HSummary
CVE-2023-49786 is a high-severity Improper Check or Handling of Exceptional Conditions (CWE-703) vulnerability in Sangoma Certified Asterisk. Its CVSS base score is 7.5 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Endpoint Denial of Service (T1499); ranked in the top 8% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2023-53705
Vulnerability Data
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…
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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.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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V10.4.2V10.4.5V15.1.3V15.4.1
Likely Mitigating Controls AI
Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.
Implements explicit check and handling for the exceptional condition of audit logging process failure.
Accurate timestamps from internal clocks enable detection of race conditions by providing reliable event ordering in audit logs.
Establishing and monitoring system metrics with correlation and response actions helps identify and address improper handling of exceptional conditions.
Provides a defined response to detected conditions by restricting operation, ensuring exceptional conditions are handled rather than ignored or mishandled.
Contingency training equips users with defined procedures to check and respond to exceptional conditions during disruptions, reducing exploitation of mishandled errors.
Testing verifies the system's ability to detect, handle, and recover from exceptional conditions as part of the plan, reducing exploitability of improper exception handling.
Regular updates keep contingency procedures aligned with system changes, providing structured handling for exceptional conditions that would otherwise allow unmitigated exploitation.
Policy defines checks and handling for exceptional conditions arising from security incidents.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Secure SDLC practices explicitly require anticipating and correctly handling exceptional conditions during design and coding.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Security testing can detect race conditions, but does not prevent them at design or coding time.
Secure SDLC mandates concurrency controls and synchronization primitives that directly prevent race conditions.
Application security requirements can specify thread-safety and locking rules, but do not prescribe implementation details.
Secure architecture principles require proper synchronization and resource isolation, addressing the root cause of CWE-362.
Secure coding standards explicitly forbid unsafe concurrent access patterns and mandate atomic operations or locks.
Reporting of unhandled errors or exceptional conditions surfaces latent failure paths so they can be corrected before exploitation.