mbed TLS up to 2.28.1/3.2.x RSA Private Key MBEDTLS_MPI_WINDOW_SIZE information exposure

Summaryinfo

A vulnerability has been found in mbed TLS up to 2.28.1/3.2.x and classified as problematic. This vulnerability affects unknown code of the component RSA Private Key Handler. This manipulation of the argument MBEDTLS_MPI_WINDOW_SIZE causes information exposure. This vulnerability is handled as CVE-2022-46392. The attack can be initiated remotely. There is not any exploit available. The affected component should be upgraded.

Detailsinfo

A vulnerability classified as problematic was found in mbed TLS up to 2.28.1/3.2.x. Affected by this vulnerability is an unknown part of the component RSA Private Key Handler. The manipulation of the argument MBEDTLS_MPI_WINDOW_SIZE with an unknown input leads to a information exposure vulnerability. The CWE definition for the vulnerability is CWE-203. The product behaves differently or sends different responses under different circumstances in a way that is observable to an unauthorized actor, which exposes 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:

An issue was discovered in Mbed TLS before 2.28.2 and 3.x before 3.3.0. An adversary with access to precise enough information about memory accesses (typically, an untrusted operating system attacking a secure enclave) can recover an RSA private key after observing the victim performing a single private-key operation, if the window size (MBEDTLS_MPI_WINDOW_SIZE) used for the exponentiation is 3 or smaller.

The weakness was released 12/16/2022. It is possible to read the advisory at github.com. This vulnerability is known as CVE-2022-46392 since 12/04/2022. 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 240979 (Debian dla-4236 : libmbedcrypto3 - security update), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 2.28.2 or 3.3.0 eliminates this vulnerability. The upgrade is hosted for download at github.com.

The vulnerability is also documented in the vulnerability database at Tenable (240979). Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Name

• mbed TLS

Version

• 2.28.0
• 2.28.1
• 3.0
• 3.1
• 3.2

CPE 2.3info

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CPE 2.2info

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

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