Mbed TLS up to 3.6.4 RSA mbedtls_mpi_mod_inv/mbedtls_mpi_gcd timing discrepancy

CVSS Meta Temp Score
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CTI Interest Score
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2.4$0-$5k0.00

Summaryinfo

A vulnerability was found in Mbed TLS up to 3.6.4. It has been rated as problematic. Affected is the function mbedtls_mpi_mod_inv/mbedtls_mpi_gcd of the component RSA Handler. This manipulation causes timing discrepancy. The identification of this vulnerability is CVE-2025-54764. The attack can only be executed locally. There is no exploit available. Upgrading the affected component is advised.

Detailsinfo

A vulnerability was found in Mbed TLS up to 3.6.4. It has been declared as problematic. Affected by this vulnerability is the function mbedtls_mpi_mod_inv/mbedtls_mpi_gcd of the component RSA Handler. The manipulation with an unknown input leads to a timing discrepancy vulnerability. The CWE definition for the vulnerability is CWE-208. Two separate operations in a product require different amounts of time to complete, in a way that is observable to an actor and reveals security-relevant information about the state of the product, such as whether a particular operation was successful or not. As an impact it is known to affect confidentiality. The summary by CVE is:

Mbed TLS before 3.6.5 allows a local timing attack against certain RSA operations, and direct calls to mbedtls_mpi_mod_inv or mbedtls_mpi_gcd.

It is possible to read the advisory at mbed-tls.readthedocs.io. This vulnerability is known as CVE-2025-54764 since 07/28/2025. The exploitation appears to be difficult. Attacking locally is a requirement. Technical details of the vulnerability are known, but there is no available exploit. The attack technique deployed by this issue is T1592 according to MITRE ATT&CK.

The vulnerability scanner Nessus provides a plugin with the ID 271658 (Linux Distros Unpatched Vulnerability : CVE-2025-54764), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 3.6.5 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at Tenable (271658). Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Vendor

Name

Version

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 2.5
VulDB Meta Temp Score: 2.4

VulDB Base Score: 2.5
VulDB Temp Score: 2.4
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Timing discrepancy
CWE: CWE-208 / CWE-203 / CWE-200
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: No

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 271658
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2025-54764

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: TLS 3.6.5

Timelineinfo

07/28/2025 CVE reserved
10/21/2025 +85 days Advisory disclosed
10/21/2025 +0 days VulDB entry created
10/28/2025 +7 days VulDB entry last update

Sourcesinfo

Advisory: mbed-tls.readthedocs.io
Status: Confirmed

CVE: CVE-2025-54764 (🔒)
GCVE (CVE): GCVE-0-2025-54764
GCVE (VulDB): GCVE-100-329119

Entryinfo

Created: 10/21/2025 08:23
Updated: 10/28/2025 01:38
Changes: 10/21/2025 08:23 (55), 10/28/2025 01:38 (2)
Complete: 🔍
Cache ID: 216::103

Be aware that VulDB is the high quality source for vulnerability data.

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