📌 이 취약점에 대해 확인된 사실
전부 발행처가 발표한 값입니다. 우리가 계산하거나 판단한 숫자는 하나도 없습니다.
악용 여부
심각도 (발행처 발표값)
높음7.1
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:Amber
악용 확률 (EPSS)
0.2%
📄 원문 그대로
아래 문장은 전부 발행처가 쓴 것입니다. 번역하지 않습니다 — 보안 문서의 오역은 조치를 바꿉니다.
취약점 설명 (NVD)
In Bouncy Castle for Java before 1.86, BLS12_381BasicScheme.keyValidate, and so BLSPublicKeyParameters and every BasicScheme, MessageAugmentation and ProofOfPossession verify and aggregateVerify that gate on it, accepted a public key built on a foreign ECCurve that merely shares BLS12-381's field characteristic. The prime-order subgroup check trusts a point's own curve to name its cofactor, since ECPoint.satisfiesOrder returns true outright when the curve's cofactor is one, so a point on a curve with a different equation and a cofactor forged to one passed keyValidate despite not being a G1 point at all. In BC's pairing implementation such a point contributes the identity in the target group, so an aggregate signature verified against a set of public keys including it is accepted even though it contains no signature for that key and message pair, admitting a phantom signer. keyValidate now first confirms that the point's curve carries exactly the canonical G1 field, equation, order and cofactor before any subgroup check. The issue is reachable only where an application constructs an ECPoint on an explicit, non-canonical curve and accepts it as an authority-bearing key; the standard 48-byte compressed-point decoder always supplies the canonical curve and was never affected.
참고
🧩 같은 약점 유형 — CWE-347
같은 분류의 다른 취약점입니다. 같은 실수가 제품을 가리지 않고 반복됩니다.