جزئیات آسیب‌پذیری

libssh2 through 1.11.1, fixed in commit 2dae302, contains an out-of-bounds heap read vulnerability in the sftp_symlink() function in src/sftp.c that allows a malicious SSH server or man-in-the-middle attacker to disclose heap memory contents or cause a crash by sending a crafted SSH_FXP_NAME response. Attackers can supply a link_len value larger than the actual packet data in SSH_FXP_NAME responses for SFTP READLINK and REALPATH operations, triggering a heap buffer over-read of up to target_len minus one bytes due to the missing validation of available packet buffer size before the memcpy operation.

• https://github.com/libssh2/libssh2/pull/1705 issue-trackingpatch
• https://github.com/libssh2/libssh2/pull/1717 issue-trackingpatch
• https://github.com/libssh2/libssh2/commit/2dae3024897e1898d389835151f4e9606227721d patch
• https://www.vulncheck.com/advisories/libssh2-heap-buffer-over-read-via-sftp-symlink-in-sftp-c third-party-advisory