EULEROS-SA-2026-3760

Summary:

An update for proftpd is now available for EulerOS V2.0SP10

EulerOS Security has rated this update as having a security impact of Important.A Common Vunlnerability Scoring System(CVSS)base score, which gives a detailed severity rating, is available for each vulnerability from the CVElink(s) in the References section.General:

ProFTPD is an enhanced FTP server with a focus toward simplicity, security,and ease of configuration. It features a very Apache-like configuration syntax, and a highly customizable server infrastructure, including support for multiple 'virtual' FTP servers, anonymous FTP, and permission-based directory visibility.

Security Fix(es):

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.(CVE-2026-53994)

In ProFTPD through 1.3.9a before 7666224, a SQL...