ID CVE-2006-5229
Summary 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. NOTE: as of 20061014, it appears that this issue is dependent on the use of manually-set passwords that causes delays when processing /etc/shadow due to an increased number of rounds.
Vulnerable Configurations
  • OpenBSD OpenSSH 4.1
  • Novell suse linux
Base: 2.6 (as of 13-10-2006 - 10:57)
  • Subverting Environment Variable Values
    The attacker directly or indirectly modifies environment variables used by or controlling the target software. The attacker's goal is to cause the target software to deviate from its expected operation in a manner that benefits the attacker.
  • Footprinting
    An attacker engages in probing and exploration activity to identify constituents and properties of the target. Footprinting is a general term to describe a variety of information gathering techniques, often used by attackers in preparation for some attack. It consists of using tools to learn as much as possible about the composition, configuration, and security mechanisms of the targeted application, system or network. Information that might be collected during a footprinting effort could include open ports, applications and their versions, network topology, and similar information. While footprinting is not intended to be damaging (although certain activities, such as network scans, can sometimes cause disruptions to vulnerable applications inadvertently) it may often pave the way for more damaging attacks.
  • Exploiting Trust in Client (aka Make the Client Invisible)
    An attack of this type exploits a programs' vulnerabilities in client/server communication channel authentication and data integrity. It leverages the implicit trust a server places in the client, or more importantly, that which the server believes is the client. An attacker executes this type of attack by placing themselves in the communication channel between client and server such that communication directly to the server is possible where the server believes it is communicating only with a valid client. There are numerous variations of this type of attack.
  • Browser Fingerprinting
    An attacker carefully crafts small snippets of Java Script to efficiently detect the type of browser the potential victim is using. Many web-based attacks need prior knowledge of the web browser including the version of browser to ensure successful exploitation of a vulnerability. Having this knowledge allows an attacker to target the victim with attacks that specifically exploit known or zero day weaknesses in the type and version of the browser used by the victim. Automating this process via Java Script as a part of the same delivery system used to exploit the browser is considered more efficient as the attacker can supply a browser fingerprinting method and integrate it with exploit code, all contained in Java Script and in response to the same web page request by the browser.
  • Session Credential Falsification through Prediction
    This attack targets predictable session ID in order to gain privileges. The attacker can predict the session ID used during a transaction to perform spoofing and session hijacking.
  • Reusing Session IDs (aka Session Replay)
    This attack targets the reuse of valid session ID to spoof the target system in order to gain privileges. The attacker tries to reuse a stolen session ID used previously during a transaction to perform spoofing and session hijacking. Another name for this type of attack is Session Replay.
  • Using Slashes in Alternate Encoding
    This attack targets the encoding of the Slash characters. An attacker would try to exploit common filtering problems related to the use of the slashes characters to gain access to resources on the target host. Directory-driven systems, such as file systems and databases, typically use the slash character to indicate traversal between directories or other container components. For murky historical reasons, PCs (and, as a result, Microsoft OSs) choose to use a backslash, whereas the UNIX world typically makes use of the forward slash. The schizophrenic result is that many MS-based systems are required to understand both forms of the slash. This gives the attacker many opportunities to discover and abuse a number of common filtering problems. The goal of this pattern is to discover server software that only applies filters to one version, but not the other.
exploit-db via4
description Portable OpenSSH <= 3.6.1p-PAM / 4.1-SUSE Timing Attack Exploit. CVE-2003-0190,CVE-2006-5229. Remote exploits for multiple platform
id EDB-ID:3303
last seen 2016-01-31
modified 2007-02-13
published 2007-02-13
reporter Marco Ivaldi
title Portable OpenSSH <= 3.6.1p-PAM / 4.1-SUSE Timing Attack Exploit
metasploit via4
description This module uses a malformed packet or timing attack to enumerate users on an OpenSSH server. The default action sends a malformed (corrupted) SSH_MSG_USERAUTH_REQUEST packet using public key authentication (must be enabled) to enumerate users. On some versions of OpenSSH under some configurations, OpenSSH will return a "permission denied" error for an invalid user faster than for a valid user, creating an opportunity for a timing attack to enumerate users. Testing note: invalid users were logged, while valid users were not. YMMV.
last seen 2019-03-24
modified 2018-09-15
published 2014-04-28
reliability Normal
reporter Rapid7
title SSH Username Enumeration
nessus via4
  • NASL family Misc.
    description According to its banner, the version of OpenSSH installed on the remote host is affected by multiple vulnerabilities : - A race condition exists that may allow an unauthenticated, remote attacker to crash the service or, on portable OpenSSH, possibly execute code on the affected host. Note that successful exploitation requires that GSSAPI authentication be enabled. - A flaw exists that may allow an attacker to determine the validity of usernames on some platforms. Note that this issue requires that GSSAPI authentication be enabled. - When SSH version 1 is used, an issue can be triggered via an SSH packet that contains duplicate blocks that could result in a loss of availability for the service. - On Fedora Core 6 (and possibly other systems), an unspecified vulnerability in the linux_audit_record_event() function allows remote attackers to inject incorrect information into audit logs.
    last seen 2019-02-21
    modified 2018-07-16
    plugin id 22466
    published 2006-09-28
    reporter Tenable
    title OpenSSH < 4.4 Multiple Vulnerabilities
  • NASL family Misc.
    description The version of SunSSH running on the remote host has an information disclosure vulnerability. A design flaw in the SSH specification could allow a man-in-the-middle attacker to recover up to 32 bits of plaintext from an SSH-protected connection in the standard configuration. An attacker could exploit this to gain access to sensitive information. Note that this version of SunSSH is also prone to several additional issues but Nessus did not test for them.
    last seen 2019-02-21
    modified 2018-07-31
    plugin id 55992
    published 2011-08-29
    reporter Tenable
    title SunSSH < 1.1.1 / 1.3 CBC Plaintext Disclosure
packetstorm via4
data source
last seen 2016-12-05
published 2007-02-14
reporter Marco Ivaldi
title openssh-timing.txt
refmap via4
bid 20418
  • 20061009 Re: yet another OpenSSH timing leak?
  • 20061009 yet another OpenSSH timing leak?
  • 20061010 Re: yet another OpenSSH timing leak?
  • 20061014 Re: yet another OpenSSH timing leak?
osvdb 32721
secunia 25979
vupen ADV-2007-2545
statements via4
contributor Joshua Bressers
lastmodified 2006-10-11
organization Red Hat
statement Red Hat has been unable to reproduce this flaw and believes that the reporter was experiencing behavior specific to his environment. We will not be releasing update to address this issue.
Last major update 26-08-2011 - 00:00
Published 10-10-2006 - 19:07
Last modified 17-10-2018 - 17:41
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