Ecosyste.ms: Advisories

Security Advisories: GSA_kwCzR0hTQS0zNDZoLTc0OWotcjI4d84AA7UE

PHPECC vulnerable to multiple cryptographic side-channel attacks

ECDSA Canonicalization

PHPECC is vulnerable to malleable ECDSA signature attacks.

Constant-Time Signer

When generating a new ECDSA signature, the GMPMath adapter was used. This class wraps the GNU Multiple Precision arithmetic library (GMP), which does not aim to provide constant-time implementations of algorithms.

An attacker capable of triggering many signatures and studying the time it takes to perform each operation would be able to leak the secret number, k, and thereby learn the private key.

EcDH Timing Leaks

When calculating a shared secret using the EcDH class, the scalar-point multiplication is based on the arithmetic defined by the Point class.

Even though the library implements a Montgomery ladder, the add(), mul(), and getDouble() methods on the Point class are not constant-time. This means that your ECDH private keys are leaking information about each bit of your private key through a timing side-channel.

Permalink: https://github.com/advisories/GHSA-346h-749j-r28w
JSON: https://advisories.ecosyste.ms/api/v1/advisories/GSA_kwCzR0hTQS0zNDZoLTc0OWotcjI4d84AA7UE
Source: GitHub Advisory Database
Origin: Unspecified
Severity: Critical
Classification: General
Published: 10 days ago
Updated: 10 days ago

CVSS Score: 9.1
CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Identifiers: GHSA-346h-749j-r28w
References:

• https://github.com/FriendsOfPHP/security-advisories/blob/master/mdanter/ecc/2024-04-24.yaml
• https://github.com/paragonie/phpecc/releases/tag/v2.0.0
• https://github.com/advisories/GHSA-346h-749j-r28w

Repository: https://github.com/paragonie/phpecc
Blast Radius: 24.9

Affected Packages