SecuriTricks - CVE-2024-1544

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.

Product(s) Impacted

Product	Versions
wolfSSL

Weaknesses

Common security weaknesses mapped to this vulnerability.

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.

References

https://github.com/wolfSSL/wolfssl/releases/tag/v5.7.2-stable

CVSS Score

4.1 / 10

CVSS Data - 3.1

Attack Vector: LOCAL
Attack Complexity: HIGH
Privileges Required: HIGH
Scope: UNCHANGED
Confidentiality Impact: HIGH
Integrity Impact: NONE
Availability Impact: NONE

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

View Vector String

Timeline

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

CVE-2024-1544