Cyber Resilience

CVE-2023-34967

Memory Safety in Samba ≤ 4.16.11

High EPSSMemory Safety
Published
20 July 2023
Modified
21 November 2024
Patch / advisory
CVSS Score v3.1 5.3
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
EPSS Score 0.61 99.1th percentile
Risk Priority 70 floored blend · peak EPSS

Summary

CVE-2023-34967 is a medium-severity Type Confusion (CWE-843) vulnerability in Samba Samba. Its CVSS base score is 5.3 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked in the top 0.9% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

Deeper analysis AI-assisted summary

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

A Type Confusion vulnerability exists in Samba's mdssvc RPC service for Spotlight. When parsing Spotlight mdssvc RPC packets, the dalloc_value_for_key() function returns objects from a key-value dictionary without sufficient type checking by callers. This allows an invalid pointer to reach talloc_get_size(), triggering a crash. The affected component is the shared RPC worker process that handles multiple client connections.

An unauthenticated remote attacker can send specially crafted Spotlight mdssvc RPC packets to induce the crash. Because the worker process is shared, the denial of service affects all other clients served by that worker. The vulnerability requires no privileges or user interaction and carries a CVSS score of 5.3 with an availability impact.

Red Hat has published multiple errata (RHSA-2023:6667, RHSA-2023:7139, RHSA-2024:0423, and RHSA-2024:0580) that supply patched Samba packages to address the issue. Administrators should apply the relevant updates for their distributions.

The EPSS score has reached a peak of 0.2117 with a current value of 0.1920. No information is provided on observed real-world exploitation.

EU & UK References

Vulnerability Data

A Type Confusion vulnerability was found in Samba's mdssvc RPC service for Spotlight. When parsing Spotlight mdssvc RPC packets, one encoded data structure is a key-value style dictionary where the keys are character strings, and the values can be any…

more

of the supported types in the mdssvc protocol. Due to a lack of type checking in callers of the dalloc_value_for_key() function, which returns the object associated with a key, a caller may trigger a crash in talloc_get_size() when talloc detects that the passed-in pointer is not a valid talloc pointer. With an RPC worker process shared among multiple client connections, a malicious client or attacker can trigger a process crash in a shared RPC mdssvc worker process, affecting all other clients this worker serves.

CWE(s)

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.
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.
T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
T1210 Exploitation of Remote Services Lateral Movement
Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.
T1212 Exploitation for Credential Access Credential Access
Adversaries may exploit software vulnerabilities in an attempt to collect credentials.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2023-34966Same product: Debian Debian Linux
CVE-2023-4352Same product: Debian Debian Linux
CVE-2023-2724Same product: Debian Debian Linux
CVE-2023-3216Same product: Debian Debian Linux
CVE-2023-6348Same product: Debian Debian Linux
CVE-2021-21224Same product: Debian Debian Linux
CVE-2020-6418Same product: Debian Debian Linux
CVE-2023-4762Same product: Debian Debian Linux
CVE-2023-2033Same product: Debian Debian Linux
CVE-2023-34968Same product: Debian Debian Linux

Affected Assets

samba
samba
≤ 4.16.11 · 4.17.0 — 4.17.10 · 4.18.0 — 4.18.5
fedoraproject
fedora
37, 38
redhat
enterprise linux
8.0, 9.0
debian
debian linux
11.0, 12.0

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)
  • V1.5.2
  • V3.2.3
  • V15.3.5

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 directly prevent type-confusion flaws via safe typing, static analysis, and code review while the control itself addresses many additional weaknesses.

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.

finds

Security testing in development can detect type-confusion vulnerabilities through fuzzing and static analysis.

prevents

Secure SDLC mandates type-safe design and review that can catch type-confusion flaws.

prevents

Application security requirements can specify strong typing and interface contracts that reduce type confusion.

prevents

Secure architecture principles promote type-safe languages and memory-safety mechanisms that mitigate type confusion.

prevents

Secure coding standards directly forbid unsafe type casts and require static-analysis checks for type confusion.

References