Vulnerabilities > CVE-2020-2099 - Use of Insufficiently Random Values vulnerability in Jenkins
Attack vector
NETWORK Attack complexity
LOW Privileges required
NONE Confidentiality impact
HIGH Integrity impact
LOW Availability impact
LOW Summary
Jenkins 2.213 and earlier, LTS 2.204.1 and earlier improperly reuses encryption key parameters in the Inbound TCP Agent Protocol/3, allowing unauthorized attackers with knowledge of agent names to obtain the connection secrets for those agents, which can be used to connect to Jenkins, impersonating those agents.
Vulnerable Configurations
Common Weakness Enumeration (CWE)
Common Attack Pattern Enumeration and Classification (CAPEC)
- Brute Force In this attack, some asset (information, functionality, identity, etc.) is protected by a finite secret value. The attacker attempts to gain access to this asset by using trial-and-error to exhaustively explore all the possible secret values in the hope of finding the secret (or a value that is functionally equivalent) that will unlock the asset. Examples of secrets can include, but are not limited to, passwords, encryption keys, database lookup keys, and initial values to one-way functions. The key factor in this attack is the attackers' ability to explore the possible secret space rapidly. This, in turn, is a function of the size of the secret space and the computational power the attacker is able to bring to bear on the problem. If the attacker has modest resources and the secret space is large, the challenge facing the attacker is intractable. While the defender cannot control the resources available to an attacker, they can control the size of the secret space. Creating a large secret space involves selecting one's secret from as large a field of equally likely alternative secrets as possible and ensuring that an attacker is unable to reduce the size of this field using available clues or cryptanalysis. Doing this is more difficult than it sounds since elimination of patterns (which, in turn, would provide an attacker clues that would help them reduce the space of potential secrets) is difficult to do using deterministic machines, such as computers. Assuming a finite secret space, a brute force attack will eventually succeed. The defender must rely on making sure that the time and resources necessary to do so will exceed the value of the information. For example, a secret space that will likely take hundreds of years to explore is likely safe from raw-brute force attacks.
- Signature Spoofing by Key Recreation An attacker obtains an authoritative or reputable signer's private signature key by exploiting a cryptographic weakness in the signature algorithm or pseudorandom number generation and then uses this key to forge signatures from the original signer to mislead a victim into performing actions that benefit the attacker.
- 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 family | FreeBSD Local Security Checks |
| NASL id | FREEBSD_PKG_A250539DD1D44591AFD3C8BDFAC335D8.NASL |
| description | Jenkins Security Advisory : Description(High) SECURITY-1682 / CVE-2020-2099 Inbound TCP Agent Protocol/3 authentication bypass (Medium) SECURITY-1641 / CVE-2020-2100 Jenkins vulnerable to UDP amplification reflection attack (Medium) SECURITY-1659 / CVE-2020-2101 Non-constant time comparison of inbound TCP agent connection secret (Medium) SECURITY-1660 / CVE-2020-2102 Non-constant time HMAC comparison (Medium) SECURITY-1695 / CVE-2020-2103 Diagnostic page exposed session cookies (Medium) SECURITY-1650 / CVE-2020-2104 Memory usage graphs accessible to anyone with Overall/Read (Low) SECURITY-1704 / CVE-2020-2105 Jenkins REST APIs vulnerable to clickjacking (Medium) SECURITY-1680 / CVE-2020-2106 Stored XSS vulnerability in Code Coverage API Plugin (Medium) SECURITY-1565 / CVE-2020-2107 Fortify Plugin stored credentials in plain text (High) SECURITY-1719 / CVE-2020-2108 XXE vulnerability in WebSphere Deployer Plugin |
| last seen | 2020-06-01 |
| modified | 2020-06-02 |
| plugin id | 133329 |
| published | 2020-01-30 |
| reporter | This script is Copyright (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof. |
| source | https://www.tenable.com/plugins/nessus/133329 |
| title | FreeBSD : jenkins -- multiple vulnerabilities (a250539d-d1d4-4591-afd3-c8bdfac335d8) |
| code | |
Redhat
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References
- https://jenkins.io/security/advisory/2020-01-29/#SECURITY-1682
- http://www.openwall.com/lists/oss-security/2020/01/29/1
- https://access.redhat.com/errata/RHBA-2020:0675
- https://access.redhat.com/errata/RHBA-2020:0402
- https://access.redhat.com/errata/RHSA-2020:0681
- https://access.redhat.com/errata/RHSA-2020:0683