Cyber Resilience

CVE-2024-29195

Memory Safety in Microsoft Azure C Shared Utility ≤ 2023-12-01

Memory Safety
Published
26 March 2024
Modified
17 June 2026
Patch / advisory
View advisory
CVSS Score v3.1 6.0
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:H/I:H/A:L
EPSS Score 0.050 91th percentile
Risk Priority 52 floored blend · peak EPSS

Summary

CVE-2024-29195 is a medium-severity Classic Buffer Overflow (CWE-120) vulnerability in Microsoft Azure C Shared Utility. Its CVSS base score is 6.0 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked in the top 9% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SI-10 (Information Input Validation) — see the control section below for these in your framework.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

The azure-c-shared-utility C library, used by the Azure IoT C SDK for AMQP and MQTT communication with Azure IoT Hub, contains a flaw in its parameter-checking logic for buffer length values. An attacker-supplied length can trigger integer wraparound, under-allocation, or a subsequent heap buffer overflow (CWE-120), potentially enabling remote code execution on an IoT device.

Exploitation requires a compromised Azure account that can inject malformed payloads through IoT Hub, the ability to exceed the service’s 128 KB message-size limit, and sufficient control to overwrite executable memory. Under these conditions an attacker can achieve arbitrary code execution on the affected device.

The vulnerability was addressed in commit 1129147c38ac02ad974c4c701a1e01b2141b9fe2 of azure-c-shared-utility; the corresponding GitHub Security Advisory GHSA-m8wp-hc7w-x4xg recommends updating to a patched version of the library.

EPSS for the CVE rose from low values to a peak of 0.0592 on 2025-12-18 before receding to the current 0.0242, indicating a measurable increase in exploitation interest after public disclosure.

EU & UK References

Vulnerability Data

The azure-c-shared-utility is a C library for AMQP/MQTT communication to Azure Cloud Services. This library may be used by the Azure IoT C SDK for communication between IoT Hub and IoT Hub devices. An attacker can cause an integer wraparound…

more

or under-allocation or heap buffer overflow due to vulnerabilities in parameter checking mechanism, by exploiting the buffer length parameter in Azure C SDK, which may lead to remote code execution. Requirements for RCE are 1. Compromised Azure account allowing malformed payloads to be sent to the device via IoT Hub service, 2. By passing IoT hub service max message payload limit of 128KB, and 3. Ability to overwrite code space with remote code. Fixed in commit https://github.com/Azure/azure-c-shared-utility/commit/1129147c38ac02ad974c4c701a1e01b2141b9fe2.

CWE(s)
CWE-120

Related Threats

MITRE ATT&CK Enterprise Techniques

T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
attack.mitre.org →
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
attack.mitre.org →
T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
attack.mitre.org →
T1210 Exploitation of Remote Services Lateral Movement
Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.
attack.mitre.org →
T1212 Exploitation for Credential Access Credential Access
Adversaries may exploit software vulnerabilities in an attempt to collect credentials.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2006-2492Same vendor: Microsoft
CVE-2013-1331Same vendor: Microsoft
CVE-2017-7269Same vendor: Microsoft
CVE-2004-0210Same vendor: Microsoft
CVE-2016-0099Same vendor: Microsoft
CVE-2010-2572Same vendor: Microsoft
CVE-2026-57246Same vendor: Microsoft
CVE-2023-40250Same vendor: Microsoft
CVE-2023-28741Same vendor: Microsoft
CVE-2023-33149Same vendor: Microsoft

Affected Assets

microsoft
azure c shared utility
≤ 2023-12-01

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)
  • V5.2.1

Mitigating Controls (NIST 800-53 r5) AI

SA-11 Developer Testing and Evaluation good match

Developer testing and analysis can find missing size checks before deployment.

SI-10 Information Input Validation good match

Input validation directly enforces size checks before buffer copies.

SA-8 Security and Privacy Engineering Principles partial match

Engineering principles require bounds checking and safe buffer handling in design.

SI-16 Memory Protection partial match

Memory protection limits the impact of an overflow once it occurs.

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 development practices directly enforce bounds checking and input validation that prevent classic buffer overflows.

ID.RA-01 partial match
prevents

Vulnerability identification processes such as code review or scanning detect classic buffer overflows before exploitation.

PR.PS-02 partial match
prevents

Routine patching replaces vulnerable code containing unchecked buffer copies with corrected versions.

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.8.28 Secure coding mostly match
prevents

Secure coding directly requires bounds-checked memory operations, addressing the root cause of CWE-120.

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

Security testing in development and acceptance can detect buffer overflows through fuzzing and static analysis, though it does not prevent them at the source.

A.8.25 Secure development life cycle partial match
prevents

Secure development life cycle mandates processes that can include input validation and bounds checking to prevent buffer overflows.

A.8.26 Application security requirements partial match
prevents

Application security requirements can specify input-size validation and safe buffer handling to mitigate classic buffer overflows.

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

Secure system architecture and engineering principles promote defensive coding patterns that reduce the likelihood of unchecked buffer copies.

References