Openssh Security Vulnerabilities

CVE-1999-1010

An SSH 1.2.27 server allows a client to use the "none" cipher, even if it is not allowed by the server policy.

CVE-2000-0143

The SSH protocol server sshd allows local users without shell access to redirect a TCP connection through a service that uses the standard system password database for authentication, such as POP or FTP.

CVE-2000-0217

The default configuration of SSH allows X forwarding, which could allow a remote attacker to control a client's X sessions via a malicious xauth program.

CVE-2000-0525

OpenSSH does not properly drop privileges when the UseLogin option is enabled, which allows local users to execute arbitrary commands by providing the command to the ssh daemon.

CVE-2000-0992

Directory traversal vulnerability in scp in sshd 1.2.xx allows a remote malicious scp server to overwrite arbitrary files via a .. (dot dot) attack.

CVE-2000-0999

Format string vulnerabilities in OpenBSD ssh program (and possibly other BSD-based operating systems) allow attackers to gain root privileges.

CVE-2000-1169

OpenSSH SSH client before 2.3.0 does not properly disable X11 or agent forwarding, which could allow a malicious SSH server to gain access to the X11 display and sniff X11 events, or gain access to the ssh-agent.

CVE-2001-0144

CORE SDI SSH1 CRC-32 compensation attack detector allows remote attackers to execute arbitrary commands on an SSH server or client via an integer overflow.

CVE-2001-0361

Implementations of SSH version 1.5, including (1) OpenSSH up to version 2.3.0, (2) AppGate, and (3) ssh-1 up to version 1.2.31, in certain configurations, allow a remote attacker to decrypt and/or alter traffic via a "Bleichenbacher attack" on PKCS#1 version 1.5.

CVE-2001-0529

OpenSSH version 2.9 and earlier, with X forwarding enabled, allows a local attacker to delete any file named 'cookies' via a symlink attack.

CVE-2001-0572

The SSH protocols 1 and 2 (aka SSH-2) as implemented in OpenSSH and other packages have various weaknesses which can allow a remote attacker to obtain the following information via sniffing: (1) password lengths or ranges of lengths, which simplifies brute force password guessing, (2) whether RSA o...

CVE-2001-0816

OpenSSH before 2.9.9, when running sftp using sftp-server and using restricted keypairs, allows remote authenticated users to bypass authorized_keys2 command= restrictions using sftp commands.

CVE-2001-0872

OpenSSH 3.0.1 and earlier with UseLogin enabled does not properly cleanse critical environment variables such as LD_PRELOAD, which allows local users to gain root privileges.

CVE-2001-1029

libutil in OpenSSH on FreeBSD 4.4 and earlier does not drop privileges before verifying the capabilities for reading the copyright and welcome files, which allows local users to bypass the capabilities checks and read arbitrary files by specifying alternate copyright or welcome files.

CVE-2001-1380

OpenSSH before 2.9.9, while using keypairs and multiple keys of different types in the ~/.ssh/authorized_keys2 file, may not properly handle the "from" option associated with a key, which could allow remote attackers to login from unauthorized IP addresses.

CVE-2001-1382

The "echo simulation" traffic analysis countermeasure in OpenSSH before 2.9.9p2 sends an additional echo packet after the password and carriage return is entered, which could allow remote attackers to determine that the countermeasure is being used.

CVE-2001-1459

OpenSSH 2.9 and earlier does not initiate a Pluggable Authentication Module (PAM) session if commands are executed with no pty, which allows local users to bypass resource limits (rlimits) set in pam.d.

CVE-2001-1507

OpenSSH before 3.0.1 with Kerberos V enabled does not properly authenticate users, which could allow remote attackers to login unchallenged.

CVE-2001-1585

SSH protocol 2 (aka SSH-2) public key authentication in the development snapshot of OpenSSH 2.3.1, available from 2001-01-18 through 2001-02-08, does not perform a challenge-response step to ensure that the client has the proper private key, which allows remote attackers to bypass authentication as...

CVE-2002-0083

Off-by-one error in the channel code of OpenSSH 2.0 through 3.0.2 allows local users or remote malicious servers to gain privileges.

CVE-2002-0575

Buffer overflow in OpenSSH before 2.9.9, and 3.x before 3.2.1, with Kerberos/AFS support and KerberosTgtPassing or AFSTokenPassing enabled, allows remote and local authenticated users to gain privileges.

CVE-2002-0639

Integer overflow in sshd in OpenSSH 2.9.9 through 3.3 allows remote attackers to execute arbitrary code during challenge response authentication (ChallengeResponseAuthentication) when OpenSSH is using SKEY or BSD_AUTH authentication.

CVE-2002-0640

Buffer overflow in sshd in OpenSSH 2.3.1 through 3.3 may allow remote attackers to execute arbitrary code via a large number of responses during challenge response authentication when OpenBSD is using PAM modules with interactive keyboard authentication (PAMAuthenticationViaKbdInt).

CVE-2002-0765

sshd in OpenSSH 3.2.2, when using YP with netgroups and under certain conditions, may allow users to successfully authenticate and log in with another user's password.

CVE-2003-0190

OpenSSH-portable (OpenSSH) 3.6.1p1 and earlier with PAM support enabled immediately sends an error message when a user does not exist, which allows remote attackers to determine valid usernames via a timing attack.

CVE-2003-0386

OpenSSH 3.6.1 and earlier, when restricting host access by numeric IP addresses and with VerifyReverseMapping disabled, allows remote attackers to bypass "from=" and "user@host" address restrictions by connecting to a host from a system whose reverse DNS hostname contains the numeric IP address.

CVE-2003-0682

"Memory bugs" in OpenSSH 3.7.1 and earlier, with unknown impact, a different set of vulnerabilities than CVE-2003-0693 and CVE-2003-0695.

CVE-2003-0693

A "buffer management error" in buffer_append_space of buffer.c for OpenSSH before 3.7 may allow remote attackers to execute arbitrary code by causing an incorrect amount of memory to be freed and corrupting the heap, a different vulnerability than CVE-2003-0695.

CVE-2003-0695

Multiple "buffer management errors" in OpenSSH before 3.7.1 may allow attackers to cause a denial of service or execute arbitrary code using (1) buffer_init in buffer.c, (2) buffer_free in buffer.c, or (3) a separate function in channels.c, a different vulnerability than CVE-2003-0693.

CVE-2003-0786

The SSH1 PAM challenge response authentication in OpenSSH 3.7.1 and 3.7.1p1, when Privilege Separation is disabled, does not check the result of the authentication attempt, which can allow remote attackers to gain privileges.

CVE-2003-0787

The PAM conversation function in OpenSSH 3.7.1 and 3.7.1p1 interprets an array of structures as an array of pointers, which allows attackers to modify the stack and possibly gain privileges.

CVE-2003-1562

sshd in OpenSSH 3.6.1p2 and earlier, when PermitRootLogin is disabled and using PAM keyboard-interactive authentication, does not insert a delay after a root login attempt with the correct password, which makes it easier for remote attackers to use timing differences to determine if the password st...

CVE-2004-0175

Directory traversal vulnerability in scp for OpenSSH before 3.4p1 allows remote malicious servers to overwrite arbitrary files. NOTE: this may be a rediscovery of CVE-2000-0992.

CVE-2004-1653

The default configuration for OpenSSH enables AllowTcpForwarding, which could allow remote authenticated users to perform a port bounce, when configured with an anonymous access program such as AnonCVS.

CVE-2004-2069

sshd.c in OpenSSH 3.6.1p2 and 3.7.1p2 and possibly other versions, when using privilege separation, does not properly signal the non-privileged process when a session has been terminated after exceeding the LoginGraceTime setting, which leaves the connection open and allows remote attackers to caus...

CVE-2004-2760

sshd in OpenSSH 3.5p1, when PermitRootLogin is disabled, immediately closes the TCP connection after a root login attempt with the correct password, but leaves the connection open after an attempt with an incorrect password, which makes it easier for remote attackers to guess the password by observ...

CVE-2005-2666

SSH, as implemented in OpenSSH before 4.0 and possibly other implementations, stores hostnames, IP addresses, and keys in plaintext in the known_hosts file, which makes it easier for an attacker that has compromised an SSH user's account to generate a list of additional targets that are more likely...

CVE-2005-2797

OpenSSH 4.0, and other versions before 4.2, does not properly handle dynamic port forwarding ("-D" option) when a listen address is not provided, which may cause OpenSSH to enable the GatewayPorts functionality.

CVE-2005-2798

sshd in OpenSSH before 4.2, when GSSAPIDelegateCredentials is enabled, allows GSSAPI credentials to be delegated to clients who log in using non-GSSAPI methods, which could cause those credentials to be exposed to untrusted users or hosts.

CVE-2006-0225

scp in OpenSSH 4.2p1 allows attackers to execute arbitrary commands via filenames that contain shell metacharacters or spaces, which are expanded twice.

CVE-2006-0883

OpenSSH on FreeBSD 5.3 and 5.4, when used with OpenPAM, does not properly handle when a forked child process terminates during PAM authentication, which allows remote attackers to cause a denial of service (client connection refusal) by connecting multiple times to the SSH server, waiting for the p...

CVE-2006-4924

sshd in OpenSSH before 4.4, when using the version 1 SSH protocol, allows remote attackers to cause a denial of service (CPU consumption) via an SSH packet that contains duplicate blocks, which is not properly handled by the CRC compensation attack detector.

CVE-2006-4925

packet.c in ssh in OpenSSH allows remote attackers to cause a denial of service (crash) by sending an invalid protocol sequence with USERAUTH_SUCCESS before NEWKEYS, which causes newkeys[mode] to be NULL.

CVE-2006-5051

Signal handler race condition in OpenSSH before 4.4 allows remote attackers to cause a denial of service (crash), and possibly execute arbitrary code if GSSAPI authentication is enabled, via unspecified vectors that lead to a double-free.

CVE-2006-5052

Unspecified vulnerability in portable OpenSSH before 4.4, when running on some platforms, allows remote attackers to determine the validity of usernames via unknown vectors involving a GSSAPI "authentication abort."

CVE-2006-5229

OpenSSH portable 4.1 on SUSE Linux, and possibly other platforms and versions, and possibly under limited configurations, allows remote attackers to determine valid usernames via timing discrepancies in which responses take longer for valid usernames than invalid ones, as demonstrated by sshtime. N...

CVE-2006-5794

Unspecified vulnerability in the sshd Privilege Separation Monitor in OpenSSH before 4.5 causes weaker verification that authentication has been successful, which might allow attackers to bypass authentication. NOTE: as of 20061108, it is believed that this issue is only exploitable by leveraging v...

CVE-2007-2243

OpenSSH 4.6 and earlier, when ChallengeResponseAuthentication is enabled, allows remote attackers to determine the existence of user accounts by attempting to authenticate via S/KEY, which displays a different response if the user account exists, a similar issue to CVE-2001-1483.

CVE-2007-2768

OpenSSH, when using OPIE (One-Time Passwords in Everything) for PAM, allows remote attackers to determine the existence of certain user accounts, which displays a different response if the user account exists and is configured to use one-time passwords (OTP), a similar issue to CVE-2007-2243.

CVE-2007-3102

Unspecified vulnerability in the linux_audit_record_event function in OpenSSH 4.3p2, as used on Fedora Core 6 and possibly other systems, allows remote attackers to write arbitrary characters to an audit log via a crafted username. NOTE: some of these details are obtained from third party informati...