Security Resilience

CVE-2023-32731

Grpc 1.53.0 – 1.55.0

Published
09 June 2023
Modified
21 November 2024
Patch / advisory
View advisory
CVSS Score v3.1 7.4
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:H
EPSS Score 0.0050 41th percentile
Risk Priority 56 floored blend · peak EPSS

CVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.

Summary

CVE-2023-32731 is a high-severity Expected Behavior Violation (CWE-440) vulnerability in Grpc Grpc. Its CVSS base score is 7.4 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Junk Data (T1001.001); ranked at the 41th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability Data

When gRPC HTTP2 stack raised a header size exceeded error, it skipped parsing the rest of the HPACK frame. This caused any HPACK table mutations to also be skipped, resulting in a desynchronization of HPACK tables between sender and receiver.…

more

If leveraged, say, between a proxy and a backend, this could lead to requests from the proxy being interpreted as containing headers from different proxy clients - leading to an information leak that can be used for privilege escalation or data exfiltration. We recommend upgrading beyond the commit contained in https://github.com/grpc/grpc/pull/33005 https://github.com/grpc/grpc/pull/33005

CWE(s)
CWE-440NVD-CWE-Other

Related Threats

MITRE ATT&CK Enterprise Techniques

T1001.001 Junk Data Command And Control
Adversaries may add junk data to protocols used for command and control to make detection more difficult.
attack.mitre.org →
T1001.002 Steganography Command And Control
Adversaries may use steganographic techniques to hide command and control traffic to make detection efforts more difficult.
attack.mitre.org →
T1001.003 Protocol or Service Impersonation Command And Control
Adversaries may impersonate legitimate protocols or web service traffic to disguise command and control activity and thwart analysis efforts.
attack.mitre.org →
T1003.002 Security Account Manager Credential Access
Adversaries may attempt to extract credential material from the Security Account Manager (SAM) database either through in-memory techniques or through the Windows Registry where the SAM database is stored.
attack.mitre.org →
T1003.008 /etc/passwd and /etc/shadow Credential Access
Adversaries may attempt to dump the contents of <code>/etc/passwd</code> and <code>/etc/shadow</code> to enable offline password cracking.
attack.mitre.org →
T1006 Direct Volume Access Stealth
Adversaries may directly access a volume to bypass file access controls and file system monitoring.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2024-7246Same product: Grpc Grpc
CVE-2024-11407Same product: Grpc Grpc
CVE-2023-1428Same product: Grpc Grpc
CVE-2023-4785Same product: Grpc Grpc
CVE-2023-33953Same product: Grpc Grpc
CVE-2026-33186Same product: Grpc Grpc
CVE-2023-32732Same product: Grpc Grpc
CVE-2024-8690Shared CWE-440
CVE-2025-27094Shared CWE-440
CVE-2025-13940Shared CWE-440

Affected Assets

grpc
grpc
1.53.0 — 1.55.0

Mitigating Controls

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.

SI-6 Security and Privacy Function Verification
addresses: CWE-440

Verification of security function operation directly detects deviations from expected behavior.

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.

ID.IM-02 partial match
blocks

Security testing and exercises help discover behavior deviations before deployment.

ID.RA-01 partial match
blocks

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

PR.PS-02 partial match
blocks

Routine software maintenance and patching can remediate discovered specification violations.

PR.PS-06 partial match
blocks

Secure SDLC practices directly enforce specification compliance and catch expected-behavior violations 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.8.19 Installation of software on operational systems partial match
removes
A.8.25 Secure development life cycle partial match
blocks

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

A.8.26 Application security requirements partial match
blocks

A.8.26 only requires that security requirements (including resilience against attacks like injections) be identified and specified during development or acquisition; it does not itself enforce, implement or assure those requirements, so the expected-behavior violation can still arise and be exploited.

A.8.27 Secure system architecture and engineering principles partial match
removes
A.8.28 Secure coding partial match
prevents

Secure coding practices enforce adherence to functional specifications during implementation.

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

Security testing in development and acceptance validates that functions behave as specified.

References