ssh-add in OpenSSH before 9.3 adds smartcard keys to ssh-agent without the intended per-hop destination constraints. The earliest affected version is 8.9.

The remote Fedora 38 host has a package installed that is affected by a vulnerability as referenced in the FEDORA-2024-2aac54ebb7 advisory.

  - ssh-add in OpenSSH before 9.3 adds smartcard keys to ssh-agent without the intended per-hop destination     constraints. The earliest affected version is 8.9. (CVE-2023-28531)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The remote Debian 11 / 12 host has packages installed that are affected by multiple vulnerabilities as referenced in the dsa-5586 advisory.

  - sshd in OpenSSH 6.2 through 8.x before 8.8, when certain non-default configurations are used, allows     privilege escalation because supplemental groups are not initialized as expected. Helper programs for     AuthorizedKeysCommand and AuthorizedPrincipalsCommand may run with privileges associated with group     memberships of the sshd process, if the configuration specifies running the command as a different user.
    (CVE-2021-41617)

  - ssh-add in OpenSSH before 9.3 adds smartcard keys to ssh-agent without the intended per-hop destination     constraints. The earliest affected version is 8.9. (CVE-2023-28531)

  - 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. (CVE-2023-48795)

  - In ssh-agent in OpenSSH before 9.6, certain destination constraints can be incompletely applied. When     destination constraints are specified during addition of PKCS#11-hosted private keys, these constraints     are only applied to the first key, even if a PKCS#11 token returns multiple keys. (CVE-2023-51384)

  - In ssh in OpenSSH before 9.6, OS command injection might occur if a user name or host name has shell     metacharacters, and this name is referenced by an expansion token in certain situations. For example, an     untrusted Git repository can have a submodule with shell metacharacters in a user name or host name.
    (CVE-2023-51385)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote Ubuntu 20.04 LTS / 22.04 LTS / 23.04 / 23.10 host has packages installed that are affected by multiple vulnerabilities as referenced in the USN-6560-1 advisory.

  - ssh-add in OpenSSH before 9.3 adds smartcard keys to ssh-agent without the intended per-hop destination     constraints. The earliest affected version is 8.9. (CVE-2023-28531)

  - 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 1.3.9rc1, ORYX CycloneSSH before 2.3.4, NetSarang XShell 7 before Build 0144,     CrushFTP before 10.6.0, ConnectBot SSH library before 2.2.22, 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; and there     could be effects on Bitvise SSH through 9.31. (CVE-2023-48795)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The version of FreeBSD installed on the remote host is prior to tested version. It is, therefore, affected by a vulnerability as referenced in the e31a8f8e-47bf-11ee-8e38-002590c1f29c advisory.

  - ssh-add in OpenSSH before 9.3 adds smartcard keys to ssh-agent without the intended per-hop destination     constraints. The earliest affected version is 8.9. (CVE-2023-28531)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The remote host is affected by the vulnerability described in GLSA-202307-01 (OpenSSH: Remote Code Execution)

  - OpenSSH server (sshd) 9.1 introduced a double-free vulnerability during options.kex_algorithms handling.
    This is fixed in OpenSSH 9.2. The double free can be leveraged, by an unauthenticated remote attacker in     the default configuration, to jump to any location in the sshd address space. One third-party report     states remote code execution is theoretically possible. (CVE-2023-25136)

  - ssh-add in OpenSSH before 9.3 adds smartcard keys to ssh-agent without the intended per-hop destination     constraints. The earliest affected version is 8.9. (CVE-2023-28531)

  -  Please review the CVE identifiers referenced below for details.  (CVE-2023-38408)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The version of OpenSSH installed on the remote host is prior to 9.3. It is, therefore, affected by multiple vulnerabilities as referenced in the release-9.3 advisory.

  - ssh-add(1): when adding smartcard keys to ssh-agent(1) with the per-hop destination constraints (ssh-add
    -h ...) added in OpenSSH 8.9, a logic error prevented the constraints from being communicated to the     agent. This resulted in the keys being added without constraints. The common cases of non-smartcard keys     and keys without destination constraints are unaffected. (CVE-2023-28531) 

  - ssh(1): Portable OpenSSH provides an implementation of the getrrsetbyname(3) function if the standard     library does not provide it, for use by the VerifyHostKeyDNS feature. A specifically crafted DNS response     could cause this function to perform an out-of-bounds read of adjacent stack data, but this condition does     not appear to be exploitable beyond denial-of- service to the ssh(1) client. The getrrsetbyname(3)     replacement is only included if the system's standard library lacks this function and portable OpenSSH was     not compiled with the ldns library (--with-ldns). getrrsetbyname(3) is only invoked if using     VerifyHostKeyDNS to fetch SSHFP records.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

ID	Name	Product	Family	Severity
190393	Fedora 38 : openssh (2024-2aac54ebb7)	Nessus	Fedora Local Security Checks	critical
187213	Debian DSA-5586-1 : openssh - security update	Nessus	Debian Local Security Checks	critical
187105	Ubuntu 20.04 LTS / 22.04 LTS / 23.04 / 23.10 : OpenSSH vulnerabilities (USN-6560-1)	Nessus	Ubuntu Local Security Checks	critical
180340	FreeBSD : FreeBSD -- ssh-add does not honor per-hop destination constraints (e31a8f8e-47bf-11ee-8e38-002590c1f29c)	Nessus	FreeBSD Local Security Checks	critical
178586	GLSA-202307-01 : OpenSSH: Remote Code Execution	Nessus	Gentoo Local Security Checks	critical
173384	OpenSSH < 9.3 Multiple Vulnerabilities	Nessus	Misc.	critical

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CVE-2023-28531

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