Proftpd

ProFTPD mod_sftp contains a heap-based buffer overflow reachable by an authenticated SFTP user. The fxp_packet_read() function accepts the attacker-supplied 32-bit big-endian SFTP packet length without a minimum sanity check. A value of 0 causes an unsigned subtraction elsewhere in the read path to underflow to approximately 4 GB. That oversized request reaches the core memory allocator, where the rounded size is computed in size_t but passed to new_block() as a 32-bit int; the low 32 bits of 0x100000000 are 0, so new_block() returns a small (~512-byte) block while the caller is told it received ~4 GB. The subsequent fill loop then streams attacker-controlled bytes past the end of the 544-byte allocation, producing an attacker-controlled heap buffer overflow. An authenticated user can crash the per-connection ProFTPD session child on demand with a single malformed SFTP packet (packet_len=0 followed by a body greater than approximately 544 bytes), producing reliable authenticated remote denial of service. Depending on heap layout and adjacent allocations, heap metadata corruption and further consequences beyond denial of service may be possible, though only denial of service is demonstrated by the supplied proof of concept.

Published: 2026-07-18T19:30:32.740Z
Updated: 2026-07-28T01:49:40.378Z

ProFTPD through 1.3.9b and 1.3.10rc2 contains an access control bypass vulnerability that allows authenticated FTP users to circumvent Directory ACL restrictions by prefixing paths with /proc/self/root in the RNFR command handler. Attackers can exploit the unresolved symlink components in dir_canonical_path() to cause dir_check() to perform lexical path comparisons that match no configured Directory block, enabling rename operations on files in DenyAll-protected directories and subsequent retrieval of those files. Mitigation: Sessions configured with DefaultRoot (chroot) are not affected, as chroot changes the directory to which /proc/self/root resolves.

Published: 2026-06-24T13:21:42.281Z
Updated: 2026-07-14T20:00:11.517Z

The Auth API in ProFTPD before 20070417, when multiple simultaneous authentication modules are configured, does not require that the module that checks authentication is the same as the module that retrieves authentication data, which might allow remote attackers to bypass authentication, as demonstrated by use of SQLAuthTypes Plaintext in mod_sql, with data retrieved from /etc/passwd.

Published: 2007-04-22T19:00:00.000Z
Updated: 2024-08-07T13:23:50.950Z

ProFTPD 1.3.0a and earlier does not properly set the buffer size limit when CommandBufferSize is specified in the configuration file, which leads to an off-by-two buffer underflow. NOTE: in November 2006, the role of CommandBufferSize was originally associated with CVE-2006-5815, but this was an error stemming from a vague initial disclosure. NOTE: ProFTPD developers dispute this issue, saying that the relevant memory location is overwritten by assignment before further use within the affected function, so this is not a vulnerability

Published: 2006-11-30T15:00:00.000Z
Updated: 2024-08-07T20:19:34.625Z

Buffer overflow in the tls_x509_name_oneline function in the mod_tls module, as used in ProFTPD 1.3.0a and earlier, and possibly other products, allows remote attackers to execute arbitrary code via a large data length argument, a different vulnerability than CVE-2006-5815.

Published: 2006-11-30T15:00:00.000Z
Updated: 2024-08-07T20:19:34.992Z