Libssh2
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By the Year
In 2025 there have been 0 vulnerabilities in Libssh2. Libssh2 did not have any published security vulnerabilities last year.
| Year | Vulnerabilities | Average Score |
|---|---|---|
| 2025 | 0 | 0.00 |
| 2024 | 0 | 0.00 |
| 2023 | 2 | 6.70 |
| 2022 | 0 | 0.00 |
| 2021 | 0 | 0.00 |
| 2020 | 0 | 0.00 |
| 2019 | 11 | 8.81 |
| 2018 | 0 | 0.00 |
It may take a day or so for new Libssh2 vulnerabilities to show up in the stats or in the list of recent security vulnerabilties. Additionally vulnerabilities may be tagged under a different product or component name.
Recent Libssh2 Security Vulnerabilities
The SSH transport protocol with certain OpenSSH extensions, found in OpenSSH before 9.6 and other products, allows remote attackers to bypass integrity checks such
CVE-2023-48795
5.9 - Medium
- December 18, 2023
The SSH transport protocol with certain OpenSSH extensions, found in OpenSSH before 9.6 and other products, allows remote attackers to bypass integrity checks such that some packets are omitted (from the extension negotiation message), and a client and server may consequently end up with a connection for which some security features have been downgraded or disabled, aka a Terrapin attack. This occurs because the SSH Binary Packet Protocol (BPP), implemented by these extensions, mishandles the handshake phase and mishandles use of sequence numbers. For example, there is an effective attack against SSH's use of ChaCha20-Poly1305 (and CBC with Encrypt-then-MAC). The bypass occurs in chacha20-poly1305@openssh.com and (if CBC is used) the -etm@openssh.com MAC algorithms. This also affects Maverick Synergy Java SSH API before 3.1.0-SNAPSHOT, Dropbear through 2022.83, Ssh before 5.1.1 in Erlang/OTP, PuTTY before 0.80, AsyncSSH before 2.14.2, golang.org/x/crypto before 0.17.0, libssh before 0.10.6, libssh2 through 1.11.0, Thorn Tech SFTP Gateway before 3.4.6, Tera Term before 5.1, Paramiko before 3.4.0, jsch before 0.2.15, SFTPGo before 2.5.6, Netgate pfSense Plus through 23.09.1, Netgate pfSense CE through 2.7.2, HPN-SSH through 18.2.0, ProFTPD before 1.3.8b (and before 1.3.9rc2), ORYX CycloneSSH before 2.3.4, NetSarang XShell 7 before Build 0144, CrushFTP before 10.6.0, ConnectBot SSH library before 2.2.22, Apache MINA sshd through 2.11.0, sshj through 0.37.0, TinySSH through 20230101, trilead-ssh2 6401, LANCOM LCOS and LANconfig, FileZilla before 3.66.4, Nova before 11.8, PKIX-SSH before 14.4, SecureCRT before 9.4.3, Transmit5 before 5.10.4, Win32-OpenSSH before 9.5.0.0p1-Beta, WinSCP before 6.2.2, Bitvise SSH Server before 9.32, Bitvise SSH Client before 9.33, KiTTY through 0.76.1.13, the net-ssh gem 7.2.0 for Ruby, the mscdex ssh2 module before 1.15.0 for Node.js, the thrussh library before 0.35.1 for Rust, and the Russh crate before 0.40.2 for Rust.
Improper Validation of Integrity Check Value
An issue was discovered in function _libssh2_packet_add in libssh2 1.10.0
CVE-2020-22218
7.5 - High
- August 22, 2023
An issue was discovered in function _libssh2_packet_add in libssh2 1.10.0 allows attackers to access out of bounds memory.
Memory Corruption
In libssh2 v1.9.0 and earlier versions
CVE-2019-17498
8.1 - High
- October 21, 2019
In libssh2 v1.9.0 and earlier versions, the SSH_MSG_DISCONNECT logic in packet.c has an integer overflow in a bounds check, enabling an attacker to specify an arbitrary (out-of-bounds) offset for a subsequent memory read. A crafted SSH server may be able to disclose sensitive information or cause a denial of service condition on the client system when a user connects to the server.
Integer Overflow or Wraparound
In libssh2 before 1.9.0, kex_method_diffie_hellman_group_exchange_sha256_key_exchange in kex.c has an integer overflow
CVE-2019-13115
8.1 - High
- July 16, 2019
In libssh2 before 1.9.0, kex_method_diffie_hellman_group_exchange_sha256_key_exchange in kex.c has an integer overflow that could lead to an out-of-bounds read in the way packets are read from the server. A remote attacker who compromises a SSH server may be able to disclose sensitive information or cause a denial of service condition on the client system when a user connects to the server. This is related to an _libssh2_check_length mistake, and is different from the various issues fixed in 1.8.1, such as CVE-2019-3855.
Out-of-bounds Read
An integer overflow flaw
CVE-2019-3856
8.8 - High
- March 25, 2019
An integer overflow flaw, which could lead to an out of bounds write, was discovered in libssh2 before 1.8.1 in the way keyboard prompt requests are parsed. A remote attacker who compromises a SSH server may be able to execute code on the client system when a user connects to the server.
Integer Overflow or Wraparound
An integer overflow flaw
CVE-2019-3857
8.8 - High
- March 25, 2019
An integer overflow flaw which could lead to an out of bounds write was discovered in libssh2 before 1.8.1 in the way SSH_MSG_CHANNEL_REQUEST packets with an exit signal are parsed. A remote attacker who compromises a SSH server may be able to execute code on the client system when a user connects to the server.
Integer Overflow or Wraparound
An out of bounds read flaw was discovered in libssh2 before 1.8.1 in the way SFTP packets with empty payloads are parsed
CVE-2019-3860
9.1 - Critical
- March 25, 2019
An out of bounds read flaw was discovered in libssh2 before 1.8.1 in the way SFTP packets with empty payloads are parsed. A remote attacker who compromises a SSH server may be able to cause a Denial of Service or read data in the client memory.
Out-of-bounds Read
An out of bounds read flaw was discovered in libssh2 before 1.8.1 in the way SSH packets with a padding length value greater than the packet length are parsed
CVE-2019-3861
9.1 - Critical
- March 25, 2019
An out of bounds read flaw was discovered in libssh2 before 1.8.1 in the way SSH packets with a padding length value greater than the packet length are parsed. A remote attacker who compromises a SSH server may be able to cause a Denial of Service or read data in the client memory.
Out-of-bounds Read
A flaw was found in libssh2 before 1.8.1
CVE-2019-3863
8.8 - High
- March 25, 2019
A flaw was found in libssh2 before 1.8.1. A server could send a multiple keyboard interactive response messages whose total length are greater than unsigned char max characters. This value is used as an index to copy memory causing in an out of bounds memory write error.
Memory Corruption
An integer overflow flaw which could lead to an out of bounds write was discovered in libssh2 before 1.8.1 in the way packets are read
CVE-2019-3855
8.8 - High
- March 21, 2019
An integer overflow flaw which could lead to an out of bounds write was discovered in libssh2 before 1.8.1 in the way packets are read from the server. A remote attacker who compromises a SSH server may be able to execute code on the client system when a user connects to the server.
Integer Overflow or Wraparound
An out of bounds read flaw was discovered in libssh2 before 1.8.1 when a specially crafted SFTP packet is received from the server
CVE-2019-3858
9.1 - Critical
- March 21, 2019
An out of bounds read flaw was discovered in libssh2 before 1.8.1 when a specially crafted SFTP packet is received from the server. A remote attacker who compromises a SSH server may be able to cause a Denial of Service or read data in the client memory.
Out-of-bounds Read
An out of bounds read flaw was discovered in libssh2 before 1.8.1 in the _libssh2_packet_require and _libssh2_packet_requirev functions
CVE-2019-3859
9.1 - Critical
- March 21, 2019
An out of bounds read flaw was discovered in libssh2 before 1.8.1 in the _libssh2_packet_require and _libssh2_packet_requirev functions. A remote attacker who compromises a SSH server may be able to cause a Denial of Service or read data in the client memory.
Out-of-bounds Read
An out of bounds read flaw was discovered in libssh2 before 1.8.1 in the way SSH_MSG_CHANNEL_REQUEST packets with an exit status message and no payload are parsed
CVE-2019-3862
9.1 - Critical
- March 21, 2019
An out of bounds read flaw was discovered in libssh2 before 1.8.1 in the way SSH_MSG_CHANNEL_REQUEST packets with an exit status message and no payload are parsed. A remote attacker who compromises a SSH server may be able to cause a Denial of Service or read data in the client memory.
Out-of-bounds Read
The kex_agree_methods function in libssh2 before 1.5.0
CVE-2015-1782
- March 13, 2015
The kex_agree_methods function in libssh2 before 1.5.0 allows remote servers to cause a denial of service (crash) or have other unspecified impact via crafted length values in an SSH_MSG_KEXINIT packet.
Improper Input Validation
