Cyber Resilience

CVE-2023-6129

Memory Safety in Openssl 3.0.0 – 3.0.12

Published
09 January 2024
Modified
12 May 2026
Patch / advisory
CVSS Score v3.1 6.5
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H
EPSS Score 0.023 82th percentile
Risk Priority 55 floored blend · peak EPSS

Summary

CVE-2023-6129 is a medium-severity Expected Behavior Violation (CWE-440) vulnerability in Openssl Openssl. Its CVSS base score is 6.5 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked in the top 18% 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-6 (Security and Privacy Function Verification) — see the control section below for these in your framework.

EU & UK References

Vulnerability Data

Issue summary: The POLY1305 MAC (message authentication code) implementation contains a bug that might corrupt the internal state of applications running on PowerPC CPU based platforms if the CPU provides vector instructions. Impact summary: If an attacker can influence whether…

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the POLY1305 MAC algorithm is used, the application state might be corrupted with various application dependent consequences. The POLY1305 MAC (message authentication code) implementation in OpenSSL for PowerPC CPUs restores the contents of vector registers in a different order than they are saved. Thus the contents of some of these vector registers are corrupted when returning to the caller. The vulnerable code is used only on newer PowerPC processors supporting the PowerISA 2.07 instructions. The consequences of this kind of internal application state corruption can be various - from no consequences, if the calling application does not depend on the contents of non-volatile XMM registers at all, to the worst consequences, where the attacker could get complete control of the application process. However unless the compiler uses the vector registers for storing pointers, the most likely consequence, if any, would be an incorrect result of some application dependent calculations or a crash leading to a denial of service. The POLY1305 MAC algorithm is most frequently used as part of the CHACHA20-POLY1305 AEAD (authenticated encryption with associated data) algorithm. The most common usage of this AEAD cipher is with TLS protocol versions 1.2 and 1.3. If this cipher is enabled on the server a malicious client can influence whether this AEAD cipher is used. This implies that TLS server applications using OpenSSL can be potentially impacted. However we are currently not aware of any concrete application that would be affected by this issue therefore we consider this a Low severity security issue.

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.
T1211 Exploitation for Stealth Stealth
Adversaries may exploit vulnerabilities to evade detection by hiding activity, suppressing logging, or operating within trusted or unmonitored components.
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.

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CVE-2023-23456Shared CWE-787
CVE-2024-20067Shared CWE-787
CVE-2024-11793Shared CWE-787
CVE-2024-20103Shared CWE-787
CVE-2023-24130Shared CWE-787

Affected Assets

openssl
openssl
3.2.0 · 3.0.0 — 3.0.12 · 3.1.0 — 3.1.4

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

Developer testing and evaluation directly checks whether implemented functions match their specifications.

Security function verification confirms that functions operate according to their defined expected behavior.

Requiring documented secure-development standards and tools can mandate bounds-checked coding practices that avoid the weakness.

Requiring a documented security architecture and design reduces the chance that implementation deviates from intended behavior.

Input validation can structurally reject or sanitize data that would otherwise trigger an out-of-bounds write.

Memory-protection mechanisms limit the exploitability and blast radius of a successful out-of-bounds write.

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 full match
prevents

Secure SDLC practices directly enforce specification compliance and catch expected-behavior violations during development.

ID.IM-02 partial match
prevents

Security testing and exercises help discover behavior deviations before deployment.

ID.RA-01 partial match
prevents

Vulnerability identification can surface spec-violating flaws, while eliminating the weakness reduces some vulnerability backlog.

PR.PS-02 partial match
prevents

Routine software maintenance and patching can remediate discovered specification violations.

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 and acceptance validates that functions behave as specified.

prevents

Secure development life cycle mandates verification against specifications, directly reducing expected-behavior violations.

prevents

Application security requirements explicitly define expected behavior that must be met.

prevents

Secure architecture and engineering principles reduce the likelihood of buffer overflows.

prevents

Secure coding practices enforce adherence to functional specifications during implementation.

finds

Change management can catch specification deviations introduced by modifications.

References