CVE-2020-15720
Description
A flaw was found in PKI, where the dogtag's pki.client.PKIConnection class disables the python-requests certificate validation. This flaw allows an attacker to intercept a connection between a FreeIPA client and a server, and execute an active Man-in-the-Middle attack. The highest threat from this vulnerability is to confidentiality and integrity.
Statement
In PKI, the pki.client.PKIConnection python class is used by the pki-server and pkispawn commands. pki-server runs locally on the server, thus not subject to a Person in the Middle attack. pkispawn may access remote node in decentralized or cloned contexts.
Identity Management (IPA) command line interface (the vault related sub-commands) may call pki.client.PKIConnection().
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 6.8 | 6.8 | N/A |
| Attack Vector | Network | Network | N/A |
| Attack Complexity | High | High | N/A |
| Privileges Required | None | None | N/A |
| User Interaction | Required | Required | N/A |
| Scope | Unchanged | Unchanged | N/A |
| Confidentiality | High | High | N/A |
| Integrity Impact | High | High | N/A |
| Availability Impact | None | None | N/A |
Vector
Red Hat: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N
NVD: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N
Red Hat CVSS v3 Score Explanation
Red Hat's choice with regards to the CVSS scoring :
UI:R : The attacker needs to wait for a client to make a connection, and intercept it. This would happen only on user request (e.g.: ipa vault sub-commands)
A:N : Because the attack requires to actively intercept and modify the network connection, Availability is not taken into account, since the attacker needs to have the power to also prevent the connection from happening, independently from the vulnerability.
Understanding the Weakness (CWE)
Integrity,Authentication
Technical Impact: Bypass Protection Mechanism; Gain Privileges or Assume Identity
When a certificate is invalid or malicious, it might allow an attacker to spoof a trusted entity by interfering in the communication path between the host and client. The product might connect to a malicious host while believing it is a trusted host, or the product might be deceived into accepting spoofed data that appears to originate from a trusted host.
Acknowledgements
Red Hat would like to thank Christian Heimes for reporting this issue.
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