Cyber Resilience

CVE-2025-49832

Memory Safety in Sangoma Certified Asterisk ≤ 18.9

Public PoCMemory Safety
Published
01 August 2025
Modified
17 June 2026
Patch / advisory
View advisory
CVSS Score v3.1 6.5
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
EPSS Score 0.0045 37th percentile
Risk Priority 52 floored blend · peak EPSS

Summary

CVE-2025-49832 is a medium-severity NULL Pointer Dereference (CWE-476) vulnerability in Sangoma Certified Asterisk. Its CVSS base score is 6.5 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Endpoint Denial of Service (T1499); ranked at the 37th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SA-15 (Development Process, Standards, and Tools) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

A10:2025 Mishandling of Exceptional Conditions

EU & UK References

Vulnerability Data

Asterisk is an open source private branch exchange and telephony toolkit. In versions up to and including 18.26.2, between 20.00.0 and 20.15.0, 20.7-cert6, 21.00.0, 22.00.0 through 22.5.0, there is a remote DoS and possible RCE condition in `asterisk/res/res_stir_shaken /verification.c` that…

more

can be exploited when an attacker can set an arbitrary Identity header, or STIR/SHAKEN is enabled, with verification set in the SIP profile associated with the endpoint to be attacked. This is fixed in versions 18.26.3, 20.7-cert6, 20.15.1, 21.10.1 and 22.5.1.

CWE(s)
CWE-476

Related Threats

MITRE ATT&CK Enterprise Techniques

T1499 Endpoint Denial of Service Impact
Adversaries may perform Endpoint Denial of Service (DoS) attacks to degrade or block the availability of services to users.
attack.mitre.org →
T1499.004 Application or System Exploitation Impact
Adversaries may exploit software vulnerabilities that can cause an application or system to crash and deny availability to users.
attack.mitre.org →
T1489 Service Stop Impact
Adversaries may stop or disable services on a system to render those services unavailable to legitimate users.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2024-42491Same product: Sangoma Asterisk
CVE-2025-54995Same product: Sangoma Asterisk
CVE-2025-47779Same product: Sangoma Asterisk
CVE-2025-47780Same product: Sangoma Asterisk
CVE-2026-23741Same product: Sangoma Asterisk
CVE-2026-23740Same product: Sangoma Asterisk
CVE-2025-1131Same product: Sangoma Asterisk
CVE-2026-23739Same product: Sangoma Asterisk
CVE-2026-23738Same product: Sangoma Asterisk
CVE-2024-57520Same product: Sangoma Asterisk

Affected Assets

sangoma
asterisk
≤ 18.26.3 · 20.0.0 — 20.15.1 · 21.0.0 — 21.10.1
sangoma
certified asterisk
20.7 · ≤ 18.9

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

SA-11 Developer Testing and Evaluation good match

Developer testing and evaluation (including static analysis) directly finds null-dereference bugs before deployment.

SA-15 Development Process, Standards, and Tools partial match

Documented development standards and tools can enforce null-safety rules and safe pointer usage.

SA-8 Security and Privacy Engineering Principles partial match

Engineering principles can mandate defensive coding such as explicit null checks before dereference.

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.

PR.PS-06 mostly match
prevents

Secure SDLC practices (static analysis, code review, safe coding standards) directly prevent NULL dereference bugs during development.

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.

A.8.29 Security testing in development and acceptance mostly match
finds

Security testing can detect NULL dereference defects before release.

A.8.25 Secure development life cycle partial match
prevents

Secure SDLC mandates defensive coding practices that can prevent NULL dereferences.

A.8.26 Application security requirements partial match
prevents

Application security requirements can specify input validation and pointer-safety rules.

A.8.27 Secure system architecture and engineering principles partial match
prevents

Secure architecture principles encourage defensive design that avoids unsafe pointer use.

A.8.28 Secure coding partial match
prevents

Secure coding standards directly require NULL-pointer checks and safe dereference patterns.

References