RSA private-key recovery via local timing side channel
Published Oct 20, 2025 · Updated Oct 20, 2025
Timing side channel in Mbed TLS before 3.6.5 allows local users to recover RSA private keys during vulnerable RSA operations. The modular inversion and GCD routines expose secret-dependent execution timing, allowing a co-resident observer to trace the victim process and reconstruct routine inputs. Demonstrated attacks require same-core code execution on affected Arm-v9 CPUs or access from the non-secure world in a TrustZone-M deployment; some additional RSA paths require MBEDTLS_RSA_NO_CRT.
Summary
What happened
Timing side channel in Mbed TLS before 3.6.5 allows local users to recover RSA private keys during vulnerable RSA operations. The modular inversion and GCD routines expose secret-dependent execution timing, allowing a co-resident observer to trace the victim process and reconstruct routine inputs. Demonstrated attacks require same-core code execution on affected Arm-v9 CPUs or access from the non-secure world in a TrustZone-M deployment; some additional RSA paths require MBEDTLS_RSA_NO_CRT.
The record
- CVE
- CVE-2025-54764
- Published
- Oct 20, 2025
- Updated
- Oct 20, 2025
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- CWE-208, T1552.004
- Attack vector
- local
- Privileges
- unauthenticated
Timeline
How it unfolded
- Oct 20, 2025CVE publishedPublication date reported by the CVE source.
- Oct 20, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
What conditions does exploitation require?
What is affected?
Affected products and versions are unavailable in this record.
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- SSBleed proof-of-conceptsproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo