Vulnerabilities > CVE-2017-12868 - Session Fixation vulnerability in Simplesamlphp

047910
CVSS 7.5 - HIGH
Attack vector
NETWORK
Attack complexity
LOW
Privileges required
NONE
Confidentiality impact
PARTIAL
Integrity impact
PARTIAL
Availability impact
PARTIAL
network
low complexity
simplesamlphp
php
CWE-384
nessus

Summary

The secureCompare method in lib/SimpleSAML/Utils/Crypto.php in SimpleSAMLphp 1.14.13 and earlier, when used with PHP before 5.6, allows attackers to conduct session fixation attacks or possibly bypass authentication by leveraging missing character conversions before an XOR operation.

Vulnerable Configurations

Part Description Count
Application
Simplesamlphp
70
Application
Php
1

Common Weakness Enumeration (CWE)

Common Attack Pattern Enumeration and Classification (CAPEC)

  • Session Credential Falsification through Forging
    An attacker creates a false but functional session credential in order to gain or usurp access to a service. Session credentials allow users to identify themselves to a service after an initial authentication without needing to resend the authentication information (usually a username and password) with every message. If an attacker is able to forge valid session credentials they may be able to bypass authentication or piggy-back off some other authenticated user's session. This attack differs from Reuse of Session IDs and Session Sidejacking attacks in that in the latter attacks an attacker uses a previous or existing credential without modification while, in a forging attack, the attacker must create their own credential, although it may be based on previously observed credentials.
  • Exploitation of Session Variables, Resource IDs and other Trusted Credentials
    Attacks on session IDs and resource IDs take advantage of the fact that some software accepts user input without verifying its authenticity. For example, a message queuing system that allows service requesters to post messages to its queue through an open channel (such as anonymous FTP), authorization is done through checking group or role membership contained in the posted message. However, there is no proof that the message itself, the information in the message (such group or role membership), or indeed the process that wrote the message to the queue are authentic and authorized to do so. Many server side processes are vulnerable to these attacks because the server to server communications have not been analyzed from a security perspective or the processes "trust" other systems because they are behind a firewall. In a similar way servers that use easy to guess or spoofable schemes for representing digital identity can also be vulnerable. Such systems frequently use schemes without cryptography and digital signatures (or with broken cryptography). Session IDs may be guessed due to insufficient randomness, poor protection (passed in the clear), lack of integrity (unsigned), or improperly correlation with access control policy enforcement points. Exposed configuration and properties files that contain system passwords, database connection strings, and such may also give an attacker an edge to identify these identifiers. The net result is that spoofing and impersonation is possible leading to an attacker's ability to break authentication, authorization, and audit controls on the system.
  • Accessing/Intercepting/Modifying HTTP Cookies
    This attack relies on the use of HTTP Cookies to store credentials, state information and other critical data on client systems. The first form of this attack involves accessing HTTP Cookies to mine for potentially sensitive data contained therein. The second form of this attack involves intercepting this data as it is transmitted from client to server. This intercepted information is then used by the attacker to impersonate the remote user/session. The third form is when the cookie's content is modified by the attacker before it is sent back to the server. Here the attacker seeks to convince the target server to operate on this falsified information.
  • Manipulating Opaque Client-based Data Tokens
    In circumstances where an application holds important data client-side in tokens (cookies, URLs, data files, and so forth) that data can be manipulated. If client or server-side application components reinterpret that data as authentication tokens or data (such as store item pricing or wallet information) then even opaquely manipulating that data may bear fruit for an Attacker. In this pattern an attacker undermines the assumption that client side tokens have been adequately protected from tampering through use of encryption or obfuscation.
  • 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.

Nessus

  • NASL familyDebian Local Security Checks
    NASL idDEBIAN_DLA-1408.NASL
    descriptionCVE-2017-12872 / CVE-2017-12868 The (1) Htpasswd authentication source in the authcrypt module and (2) SimpleSAML_Session class in SimpleSAMLphp 1.14.11 and earlier allow remote attackers to conduct timing side-channel attacks by leveraging use of the standard comparison operator to compare secret material against user input. CVE-2017-12868 was a about an improper fix of CVE-2017-12872 in the initial patch released by upstream. We have used the correct patch. For Debian 8
    last seen2020-06-01
    modified2020-06-02
    plugin id110817
    published2018-07-02
    reporterThis script is Copyright (C) 2018 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/110817
    titleDebian DLA-1408-1 : simplesamlphp security update
  • NASL familyDebian Local Security Checks
    NASL idDEBIAN_DLA-1205.NASL
    descriptionThe simplesamlphp package in wheezy is vulnerable to multiple attacks on authentication-related code, leading to unauthorized access and information disclosure. CVE-2017-12867 The SimpleSAML_Auth_TimeLimitedToken class allows attackers with access to a secret token to extend its validity period by manipulating the prepended time offset. CVE-2017-12869 The multiauth module allows remote attackers to bypass authentication context restrictions and use an authentication source defined in config/authsources.php via vectors related to improper validation of user input. CVE-2017-12872 / CVE-2017-12868 The (1) Htpasswd authentication source in the authcrypt module and (2) SimpleSAML_Session class in SimpleSAMLphp 1.14.11 and earlier allow remote iattackers to conduct timing side-channel attacks by leveraging use of the standard comparison operator to compare secret material against user input. CVE-2017-12868 was a about an improper fix of CVE-2017-12872 in the initial patch released by upstream. We have used the correct patch. CVE-2017-12873 SimpleSAMLphp might allow attackers to obtain sensitive information, gain unauthorized access, or have unspecified other impacts by leveraging incorrect persistent NameID generation when an Identity Provider (IdP) is misconfigured. CVE-2017-12874 The InfoCard module for SimpleSAMLphp allows attackers to spoof XML messages by leveraging an incorrect check of return values in signature validation utilities. For Debian 7
    last seen2020-03-17
    modified2017-12-13
    plugin id105193
    published2017-12-13
    reporterThis script is Copyright (C) 2017-2020 Tenable Network Security, Inc.
    sourcehttps://www.tenable.com/plugins/nessus/105193
    titleDebian DLA-1205-1 : simplesamlphp security update