CVE‐2025‐14813

Title: : GOSTCTR implementation unable to process more than 255 blocks correctly

Issue affecting: BC 1.59 to 1.80.1, BC 1.81, BC 1.82 to BC 1.83.

Fixed versions: BC 1.80.2, BC 1.81.1, BC 1.84

Platform affected: Java 4 and later.

The GOST-R-3413-2015 CTR implementation in G3413CTRBlockCipher was using a single byte as a counter, resulting in the mode being unable to encrypt or decrypt more than 255 blocks. This is somewhat below the algorithm definition which says the counter should allow for n/2 bits where n is the block size of the cipher in use.

Fixes for this were introduced in commit b42574345414e4b7c8051b16fa1fafe01c29871f and commit 701686cb0184cd9ae103c801b3581fdf95c6d4f3.