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Lemur subject to insecure random generation

High severity GitHub Reviewed Published Feb 28, 2023 in Netflix/lemur • Updated Sep 30, 2024

Package

pip lemur (pip)

Affected versions

< 1.3.2

Patched versions

1.3.2

Description

Overview

Lemur was using insecure random generation for its example configuration file, as well as for some utilities.

Impact

The potentially affected generated items include:

Configuration item Config option name (if applicable) Documentation link (if applicable) Rotation option Code reference(s)
Flask session secret SECRET_KEY Flask documentation Generate a new secret and place in config; all existing sessions will be invalidated N/A, internal to Flask
Lemur token secret LEMUR_TOKEN_SECRET Lemur's configuration documentation Generate a new secret and place in config; all existing JWTs will be invalidated and must be regenerated (including API keys) 1, 2
Lemur database encryption key LEMUR_ENCRYPTION_KEYS Lemur's configuration documentation A new key can be generated and added to this list, but existing data encrypted with prior keys cannot be re-encrypted unless you write a custom re-encryption process 1
OAuth2 state token secret key OAUTH_STATE_TOKEN_SECRET Lemur's configuration documentation Generate a new secret and place in config 1
Randomly generated passphrases for openssl keystores N/A, generated at runtime but persisted N/A Re-export all openssl keystores and replace them wherever they're in use 1
Initial password for LDAP users N/A, generated at runtime but persisted N/A N/A, cannot be rotated* 1
Initial password for Ping/OAuth2 users N/A, generated at runtime but persisted N/A N/A, cannot be rotated* 1
Oauth2 nonce N/A, short-lived runtime secret N/A N/A, rotation is not required (these are short-lived) 1
Verisign certificate enrollment challenges N/A, short-lived runtime secret N/A N/A, rotation is not required (these are short-lived) 1

If your deployment of Lemur is using any of the above config secrets that were generated by Lemur's example config (i.e., generated using insecure randomness), you should rotate those config secrets. If you generated your config secrets in a more secure way, they are not known to be compromised, but you should still upgrade Lemur to ensure that you receive code fixes for the runtime-generated secrets.

For general information and guidance on Lemur secret configuration, see Lemur's configuration documentation, which includes information on many of the configuration options listed above.

*For the user passwords: Even though these users are configured to use SSO, they do get generated with valid database passwords that can be used to log in. Since Lemur doesn't have an option to change passwords (#3888), one option for rotating them would be to directly modify the value in the database to some other unguessable string (you do not need to know the plaintext password since it won't be used).

Patches

The patch is available in v1.3.2.

Workarounds

No workarounds are available.

References

N/A

References

@jtschladen jtschladen published to Netflix/lemur Feb 28, 2023
Published to the GitHub Advisory Database Mar 1, 2023
Reviewed Mar 1, 2023
Last updated Sep 30, 2024

Severity

High

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v4 base metrics

Exploitability Metrics
Attack Vector Network
Attack Complexity Low
Attack Requirements None
Privileges Required None
User interaction None
Vulnerable System Impact Metrics
Confidentiality High
Integrity None
Availability None
Subsequent System Impact Metrics
Confidentiality None
Integrity None
Availability None

CVSS v4 base metrics

Exploitability Metrics
Attack Vector: This metric reflects the context by which vulnerability exploitation is possible. This metric value (and consequently the resulting severity) will be larger the more remote (logically, and physically) an attacker can be in order to exploit the vulnerable system. The assumption is that the number of potential attackers for a vulnerability that could be exploited from across a network is larger than the number of potential attackers that could exploit a vulnerability requiring physical access to a device, and therefore warrants a greater severity.
Attack Complexity: This metric captures measurable actions that must be taken by the attacker to actively evade or circumvent existing built-in security-enhancing conditions in order to obtain a working exploit. These are conditions whose primary purpose is to increase security and/or increase exploit engineering complexity. A vulnerability exploitable without a target-specific variable has a lower complexity than a vulnerability that would require non-trivial customization. This metric is meant to capture security mechanisms utilized by the vulnerable system.
Attack Requirements: This metric captures the prerequisite deployment and execution conditions or variables of the vulnerable system that enable the attack. These differ from security-enhancing techniques/technologies (ref Attack Complexity) as the primary purpose of these conditions is not to explicitly mitigate attacks, but rather, emerge naturally as a consequence of the deployment and execution of the vulnerable system.
Privileges Required: This metric describes the level of privileges an attacker must possess prior to successfully exploiting the vulnerability. The method by which the attacker obtains privileged credentials prior to the attack (e.g., free trial accounts), is outside the scope of this metric. Generally, self-service provisioned accounts do not constitute a privilege requirement if the attacker can grant themselves privileges as part of the attack.
User interaction: This metric captures the requirement for a human user, other than the attacker, to participate in the successful compromise of the vulnerable system. This metric determines whether the vulnerability can be exploited solely at the will of the attacker, or whether a separate user (or user-initiated process) must participate in some manner.
Vulnerable System Impact Metrics
Confidentiality: This metric measures the impact to the confidentiality of the information managed by the VULNERABLE SYSTEM due to a successfully exploited vulnerability. Confidentiality refers to limiting information access and disclosure to only authorized users, as well as preventing access by, or disclosure to, unauthorized ones.
Integrity: This metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information. Integrity of the VULNERABLE SYSTEM is impacted when an attacker makes unauthorized modification of system data. Integrity is also impacted when a system user can repudiate critical actions taken in the context of the system (e.g. due to insufficient logging).
Availability: This metric measures the impact to the availability of the VULNERABLE SYSTEM resulting from a successfully exploited vulnerability. While the Confidentiality and Integrity impact metrics apply to the loss of confidentiality or integrity of data (e.g., information, files) used by the system, this metric refers to the loss of availability of the impacted system itself, such as a networked service (e.g., web, database, email). Since availability refers to the accessibility of information resources, attacks that consume network bandwidth, processor cycles, or disk space all impact the availability of a system.
Subsequent System Impact Metrics
Confidentiality: This metric measures the impact to the confidentiality of the information managed by the SUBSEQUENT SYSTEM due to a successfully exploited vulnerability. Confidentiality refers to limiting information access and disclosure to only authorized users, as well as preventing access by, or disclosure to, unauthorized ones.
Integrity: This metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information. Integrity of the SUBSEQUENT SYSTEM is impacted when an attacker makes unauthorized modification of system data. Integrity is also impacted when a system user can repudiate critical actions taken in the context of the system (e.g. due to insufficient logging).
Availability: This metric measures the impact to the availability of the SUBSEQUENT SYSTEM resulting from a successfully exploited vulnerability. While the Confidentiality and Integrity impact metrics apply to the loss of confidentiality or integrity of data (e.g., information, files) used by the system, this metric refers to the loss of availability of the impacted system itself, such as a networked service (e.g., web, database, email). Since availability refers to the accessibility of information resources, attacks that consume network bandwidth, processor cycles, or disk space all impact the availability of a system.
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N

EPSS score

0.245%
(65th percentile)

Weaknesses

CVE ID

CVE-2023-30797

GHSA ID

GHSA-5fqv-mpj8-h7gm

Source code

Credits

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