Cyber Resilience

CVE-2025-63384

Chipsalliance Rocketchip ≤ 1.6

Public PoC
Published
10 November 2025
Modified
05 February 2026
Patch / 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:H/I:N/A:N
EPSS Score 0.0030 22th percentile
Risk Priority 35 floored blend · peak EPSS

Summary

CVE-2025-63384 is a medium-severity Incorrect Privilege Assignment (CWE-266) vulnerability in Chipsalliance Rocketchip. Its CVSS base score is 6.5 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 22th 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 AC-3 (Access Enforcement) and SC-3 (Security Function Isolation) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

A vulnerability was discovered in RISC-V Rocket-Chip v1.6 and before implementation where the SRET (Supervisor-mode Exception Return) instruction fails to correctly transition the processor's privilege level. Instead of downgrading from Machine-mode (M-mode) to Supervisor-mode (S-mode) as specified by the sstatus.SPP…

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bit, the processor incorrectly remains in M-mode, leading to a critical privilege retention vulnerability.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
Why these techniques?

The SRET instruction flaw allows an attacker in M-mode to retain M-mode privileges instead of downgrading to S-mode, directly enabling privilege escalation (T1068) by abusing the broken privilege transition mechanism.

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2025-56301Same vendor: Chipsalliance
CVE-2025-26512Shared CWE-266
CVE-2026-57386Shared CWE-266
CVE-2026-48879Shared CWE-266
CVE-2025-29004Shared CWE-266
CVE-2025-62645Shared CWE-266
CVE-2025-1653Shared CWE-266
CVE-2026-35671Shared CWE-266
CVE-2026-42368Shared CWE-266
CVE-2026-57768Shared CWE-266

Affected Assets

chipsalliance
rocketchip
≤ 1.6

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)
  • AC-3 Access Enforcement
  • SC-3 Security Function Isolation
Detect
Catch it (NIST detect / respond)
  • SI-7 Software, Firmware, and Information Integrity
Harden
Shrink the surface (DISA STIG)
  • 8 hardening rules · 6 OS baselines
Validate
Prove the fix (OWASP ASVS)

Mitigating Controls (NIST 800-53 r5) AI

prevent

Directly enforces correct privilege-level transitions on SRET so that the processor cannot remain in M-mode when sstatus.SPP requires downgrade to S-mode.

prevent

Requires isolation of security functions (privilege modes) so that a flawed SRET implementation cannot allow M-mode code to execute with retained higher privileges.

detect

Verifies integrity of processor firmware and configuration, enabling detection of the incorrect privilege state left by a defective SRET instruction.

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.AA-05 full match
prevents

Directly enforces least-privilege policy definition, management, and review that prevents incorrect privilege assignments.

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.

prevents

The access-rights control governs the entire lifecycle of privilege assignment, directly eliminating incorrect assignments.

prevents

Privileged-access-rights control explicitly requires least-privilege assignment and ongoing validation, directly mitigating CWE-266.

prevents

Access control policy directly prevents incorrect privilege assignment by defining who may receive which rights.

mitigates

Segregation of duties reduces blast radius of any single incorrect privilege but does not prevent the assignment itself.

mitigates

Restricting privileged utility programs limits exposure from over-privileged accounts but does not address how privileges are assigned.

prevents

Information-access-restriction mechanisms enforce the correct privilege boundaries once assignment rules are defined.

References