VulnerabilityAnalyzed

CVE-2024-14041

An attacker able to measure the timing of a large number of decapsulations performed with the same long-term private key can recover that key.

HIGH 8.2EPSS 0.34%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.34%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

In Bouncy Castle for Java from 1.73 to before 1.78, three ML-KEM (CRYSTALS-Kyber) routines divided secret-derived polynomial coefficients by the modulus q: Poly.toMsg, which decodes the decrypted message, and the ciphertext compression routines Poly.compressPoly and PolyVec.compressPolyVec. An attacker able to measure the timing of a large number of decapsulations performed with the same long-term private key can recover that key. These are the KyberSlash1 (Poly.toMsg) and KyberSlash2 (ciphertext compression) divisions. Compression performed during encapsulation operates on values that become the public ciphertext and is not affected.

CVSS 4.0: 8.2 HIGHCVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:N/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/M
EPSS: 0.34% probability · 28th percentile
CISA KEV: Not listed
Weakness: CWE-208
Affected: bouncycastle/bc-java
Source: 91579145-5d7b-4cc5-b925-a0262ff19630

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.