Observable Differences in Behavior to Error Inputs in Bouncy Castle

中 5.3CVE-2020-26939 · GHSA-72m5-fvvv-55m6 · 02/11/2020 公開 · 17/06/2026 更新

要点

CVE-2020-26939 は org.bouncycastle:bc-fips, org.bouncycastle:bcprov-ext-jdk15on, org.bouncycastle:bcprov-ext-jdk16 に影響する深刻度「中」 (CVSS 5.3) の脆弱性です。
今後30日間に悪用される確率（EPSS）：0.92%（全脆弱性の 60.5% より高い）。
対処：1.0.2, 1.61, 1.0.1.2 以降に更新してください。

パッケージ	影響を受けるバージョン	修正済みバージョン
org.bouncycastle:bc-fips Maven	`< 1.0.2`	`1.0.2`
org.bouncycastle:bcprov-ext-jdk15on Maven	`< 1.61`	`1.61`
org.bouncycastle:bcprov-ext-jdk16 Maven	`< 1.61`	`1.61`
org.bouncycastle:bcprov-jdk14 Maven	`< 1.61`	`1.61`
org.bouncycastle:bcprov-jdk15 Maven	`< 1.61`	`1.61`
org.bouncycastle:bcprov-jdk15on Maven	`< 1.61`	`1.61`
org.bouncycastle:bcprov-jdk15to18 Maven	`< 1.61`	`1.61`
org.bouncycastle:bcprov-jdk16 Maven	`< 1.61`	`1.61`
fips java api bouncycastle	`< 1.0.1.2`	`1.0.1.2`
legion-of-the-bouncy-castle bouncycastle	`< 1.61`	`1.61`

概要

In Legion of the Bouncy Castle BC before 1.55 and BC-FJA before 1.0.2, attackers can obtain sensitive information about a private exponent because of Observable Differences in Behavior to Error Inputs. This occurs in org.bouncycastle.crypto.encodings.OAEPEncoding. Sending invalid ciphertext that decrypts to a short payload in the OAEP Decoder could result in the throwing of an early exception, potentially leaking some information about the private exponent of the RSA private key performing the encryption.

NVD の説明

In Legion of the Bouncy Castle BC before 1.61 and BC-FJA before 1.0.1.2, attackers can obtain sensitive information about a private exponent because of Observable Differences in Behavior to Error Inputs. This occurs in org.bouncycastle.crypto.encodings.OAEPEncoding. Sending invalid ciphertext that decrypts to a short payload in the OAEP Decoder could result in the throwing of an early exception, potentially leaking some information about the private exponent of the RSA private key performing the encryption.