CVE-2024-1544

Aug. 28, 2024, 12:57 p.m.

CVSS Score

4.1 / 10

Product(s) Impacted

wolfSSL

Description

Generating the ECDSA nonce k samples a random number r and then truncates this randomness with a modular reduction mod n where n is the order of the elliptic curve. Meaning k = r mod n. The division used during the reduction estimates a factor q_e by dividing the upper two digits (a digit having e.g. a size of 8 byte) of r by the upper digit of n and then decrements q_e in a loop until it has the correct size. Observing the number of times q_e is decremented through a control-flow revealing side-channel reveals a bias in the most significant bits of k. Depending on the curve this is either a negligible bias or a significant bias large enough to reconstruct k with lattice reduction methods. For SECP160R1, e.g., we find a bias of 15 bits.

Weaknesses

CWE-203
Observable Discrepancy

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.

CWE ID: 203

Date

Published: Aug. 27, 2024, 7:15 p.m.

Last Modified: Aug. 28, 2024, 12:57 p.m.

Status : Awaiting Analysis

CVE has been recently published to the CVE List and has been received by the NVD.

More info

Source

facts@wolfssl.com

CVSS Data

Attack Vector

LOCAL

Attack Complexity

HIGH

Privileges Required

HIGH

Scope

UNCHANGED

Confidentiality Impact

HIGH

Integrity Impact

NONE

Availability Impact

NONE

Base Score
4.1
Exploitability Score
0.5
Impact Score
3.6
Base Severity
MEDIUM
CVSS Vector String

The CVSS vector string provides an in-depth view of the vulnerability metrics.

View Vector String

CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:N/A:N

References