PT-2026-7473 · Unknown+4 · Cryptography+4
CVSS v3.1
9.8
Critical
| Vector | AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
Name of the Vulnerable Software and Affected Versions
cryptography versions prior to 46.0.5
Description
The
public key from numbers (or EllipticCurvePublicNumbers.public key()), EllipticCurvePublicNumbers.public key(), load der public key(), and load pem public key() functions do not validate that the provided public key point belongs to the expected prime-order subgroup of the curve. This missing validation allows an attacker to supply a public key point P from a small-order subgroup, potentially leading to security issues in signature verification (ECDSA) and shared key negotiation (ECDH). When using ECDH, the victim's private key modulo the small subgroup order may be leaked. For curves with a cofactor greater than 1, the least significant bits of the private key are revealed. Exploiting this issue with weak public keys in ECDSA enables signature forgery on the small subgroup. This issue only impacts SECT curves.Recommendations
Upgrade to cryptography version 46.0.5 or later.
Exploit
Fix
DoS
Insufficient Verification of Data Authenticity
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Related Identifiers
Affected Products
Linuxmint
Rocky Linux
Sect
Ubuntu
Cryptography