CryptX versions before 0.088_001 for Perl have a stack buffer overflow in four AEAD decrypt_verify helpers. The gcm_decrypt_verify, ccm_decrypt_verify, chacha20poly1305_decrypt_verify and eax_decrypt_verify XS routines copied the caller-supplied authentication tag into a fixed 144-byte stack buffer (MAXBLOCKSIZE) without checking the supplied length. A longer tag overwrites the stack past the buffer. Version 0.088 added the clamp to gcm_decrypt_verify, and 0.088_001 added it to the other three. Any caller of an affected helper that forwards an attacker-controlled tag longer than the buffer can trigger the overflow.

• https://github.com/DCIT/perl-CryptX/commit/57e69e541b0718ca8724c2f61514322a2d859bc1.patch
• https://github.com/DCIT/perl-CryptX/commit/7e56347d420aaf43b2ee1586f4a230492ccf1642.patch
• https://metacpan.org/release/MIK/CryptX-0.088_001