CVSS 4.0
Вероятност да бъде експлоатирана в следващите 30 дни (EPSS)
Атакува се
Време до експлоатация
Атакува се по мрежата, при специфични условия, без вход и след действие от потребителя.
- Експлоатация: няма данни за експлоатация
- Атаката не може да се автоматизира
Описание
Оригинално описание
libssh2 through 1.11.1, fixed in commit 42e33d8, contains a pre-authentication heap buffer overflow vulnerability that allows a malicious SSH server to corrupt heap metadata in any connecting client by sending a packet with a packet_length smaller than the cipher's block size during Encrypt-then-MAC cipher negotiation. In the fullpacket() function in src/transport.c, the ETM path allocates a buffer of packet_length bytes but copies blocksize minus one bytes via memcpy, causing an overflow that on 32-bit glibc writes attacker-controlled bytes into an adjacent chunk's SIZE field, enabling tcache bin confusion, overlapping live objects, and function pointer overwrite during the session handshake before authentication.
Засегнати продукти
- libssh2 libssh2: до 1.11.1; 42e33d81577ed4b95d4b4f6f845e5ee8efe5eeb4
Вид слабост
История
- 24 юли 2026 Публикувано
Други уязвимости в libssh2 libssh2
Първоизточници
- https://www.cve.org/CVERecord?id=CVE-2026-66035
- https://nvd.nist.gov/vuln/detail/CVE-2026-66035
- https://github.com/libssh2/libssh2/pull/2198
- https://github.com/libssh2/libssh2/commit/42e33d81577ed4b95d4b4f6f845e5ee8efe5eeb4
- https://www.vulncheck.com/advisories/libssh2-heap-buffer-overflow-via-etm-cipher-negotiation