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Nuclei allows unsigned code template execution through workflows

High severity GitHub Reviewed Published Mar 15, 2024 in projectdiscovery/nuclei • Updated Aug 20, 2024

Package

gomod github.com/projectdiscovery/nuclei/v3 (Go)

Affected versions

>= 3.0.0, < 3.2.0

Patched versions

3.2.0

Description

Overview

A significant security oversight was identified in Nuclei v3, involving the execution of unsigned code templates through workflows. This vulnerability specifically affects users utilizing custom workflows, potentially allowing the execution of malicious code on the user's system. This advisory outlines the impacted users, provides details on the security patch, and suggests mitigation strategies.

Affected Users

  1. CLI Users: Those executing custom workflows from untrusted sources. This includes workflows authored by third parties or obtained from unverified repositories.
  2. SDK Users: Developers integrating Nuclei into their platforms, particularly if they permit the execution of custom workflows by end-users.

Security Patch

The vulnerability is addressed in Nuclei v3.2.0. Users are strongly recommended to update to this version to mitigate the security risk.

Mitigation

  • Immediate Upgrade: The primary recommendation is to upgrade to Nuclei v3.2.0, where the vulnerability has been patched.
  • Avoid Untrusted Workflows: As an interim measure, users should refrain from using custom workflows if unable to upgrade immediately. Only trusted, verified workflows should be executed.

Details

The vulnerability stems from an oversight in the workflow execution mechanism, where unsigned code templates could be executed, bypassing the security measures intended to authenticate the integrity and source of the templates. This issue is isolated to workflow executions and does not affect direct template executions.

Workarounds

The only effective workaround, aside from upgrading, is to avoid the use of custom workflows altogether. This approach limits functionality but ensures security until the upgrade can be performed.

Acknowledgements

We extend our sincere gratitude to @gpc1996 for their diligence in identifying and reporting this vulnerability.

References

References

@ehsandeep ehsandeep published to projectdiscovery/nuclei Mar 15, 2024
Published to the GitHub Advisory Database Mar 15, 2024
Reviewed Mar 15, 2024
Published by the National Vulnerability Database Mar 15, 2024
Last updated Aug 20, 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 Present
Privileges Required None
User interaction Active
Vulnerable System Impact Metrics
Confidentiality High
Integrity High
Availability None
Subsequent System Impact Metrics
Confidentiality High
Integrity High
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:P/PR:N/UI:A/VC:H/VI:H/VA:N/SC:H/SI:H/SA:N

EPSS score

0.046%
(18th percentile)

Weaknesses

CVE ID

CVE-2024-27920

GHSA ID

GHSA-w5wx-6g2r-r78q

Source code

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