CVE-2024-38440

Netatalk 3.2.0 has an off-by-one error, and resultant heap-based buffer overflow and segmentation violation, because of incorrectly using FPLoginExt in BN_bin2bn in etc/uams/uams_dhx_pam.c. The original issue 1097 report stated: ‘The latest version of Netatalk (v3.2.0) contains a security vulnerability. This vulnerability arises due to a lack of validation for the length field after parsing user-provided data, leading to an out-of-bounds heap write of one byte (\0). Under specific configurations, this can result in reading metadata of the next heap block, potentially causing a Denial of Service (DoS) under certain heap layouts or with ASAN enabled. … The vulnerability is located in the FPLoginExt operation of Netatalk, in the BN_bin2bn function found in /etc/uams/uams_dhx_pam.c … if (!(bn = BN_bin2bn((unsigned char *)ibuf, KEYSIZE, NULL))) … threads … [#0] Id 1, Name: “afpd”, stopped 0x7ffff4304e58 in ?? (), reason: SIGSEGV … [#0] 0x7ffff4304e58 mov BYTE PTR [r14+0x8], 0x0 … mov rdx, QWORD PTR [rsp+0x18] … afp_login_ext(obj=<optimized out>, ibuf=0x62d000010424 “”, ibuflen=0xffffffffffff0015, rbuf=<optimized out>, rbuflen=<optimized out>) … afp_over_dsi(obj=0x5555556154c0 <obj>).’