Files or Directories Accessible to External Parties vulnerability in smb server in ProjectDiscovery Interactsh allows remote attackers to read/write any files in the directory and subdirectories of where the victim runs interactsh-server via anonymous login.

A domain configured with interactsh server was vulnerable to subdomain takeover for specfic subdomain, i.e app, Interactsh server before < 1.0.0 used to create cname entries for app pointing to projectdiscovery.github.io as default which intended to used for hosting interactsh web client using GitHub pages. It turns out to be a security issue with a self-hosted interactsh server in which the user may not have configured a web client but still have a cname entry pointing to GitHub pages, making them vulnerable to subdomain takeover.

This issue was initially reported to us as a subdomain takeover for one of our domains that runs interactsh server by Melih at security@projectdiscovery.io, and after conducting an internal investigation, we determined that it was an issue with the default config of interactsh server affecting all the server running self-hosted instance of interactsh, as a result - cname entry has been removed in the latest release.

Impact This allows one to host / run arbitrary client side code (XSS) in a user's browser when browsing the vulnerable subdomain, for more details on the impact, please read this detailed blogpost from Detectify. Patches Update to Interactsh server v1.0.0 with go install -v github.com/projectdiscovery/interactsh/cmd/interactsh-server@latest

References https://github.com/projectdiscovery/interactsh/issues/136

For more information If you have any questions or comments about this advisory: Email us at security@projectdiscovery.io

Summary A vulnerability has been identified in Nuclei's template signature verification system that could allow an attacker to bypass the signature check and possibly execute malicious code via custom code template.

Affected Component The vulnerability is present in the template signature verification process, specifically in the signer package.

Description The vulnerability stems from a discrepancy between how the signature verification process and the YAML parser handle newline characters, combined with the way multiple signatures are processed. This allows an attacker to inject malicious content into a template while maintaining a valid signature for the benign part of the template.

Affected Users 1. CLI Users: Those executing custom code templates from unverified sources. This includes templates 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 code templates by end-users.

[!NOTE] Code templates are disabled as default, users have to explicitly enable with -code option.

Proof of Concept

yaml id: example-template info: name: Example Template Other benign content... digest: <validsignatureforbenigncontent> digest: <anothersignature>\r code:\r - engine:\r - sh\r - bash\r source: |\r id\r Patches 1. The vulnerability is addressed in Nuclei v3.3.2 Users are strongly recommended to update to this version to mitigate the security risk. 2. Fix reference - https://github.com/projectdiscovery/nuclei/commit/0da993afe6d41b4b1b814e8fad23a2acba13c60a

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

Workarounds If you are unable to upgrade nuclei, disable running custom code templates as workaround.

Acknowledgments

We would like to thank Guy Goldenberg from Wiz who reported this to us via our security email, security@projectdiscovery.io.

ProjectDiscovery Nuclei 3 before 3.8.0 allows DSL expression injection. This affects use of -env-vars for multi-step templates against untrusted targets (not the default configuration).

Overview

We have identified and addressed a security issue in the Nuclei project that affected users utilizing Nuclei as Go code (SDK) running custom templates. This issue did not affect CLI users. The problem was related to sanitization issues with payloads loading in sandbox mode.

Details

In the previous versions, there was a potential risk with payloads loading in sandbox mode. The issue occurred due to relative paths not being converted to absolute paths before doing the check for sandbox flag allowing arbitrary files to be read on the filesystem in certain cases when using Nuclei from Go SDK implementation.

This issue has been fixed in the latest release, v2.9.9. We have also enabled sandbox by default for filesystem loading. This can be optionally disabled if required.

The -sandbox option has been deprecated and is now divided into two new options: -lfa (allow local file access) which is disabled by default and -lna (restrict local network access) which can be optionally disabled by user. The -lfa allows file (payload) access anywhere on the system (disabling sandbox effectively), and -lna blocks connections to the local/private network.

Affected Versions

This issue affected all versions of Nuclei prior to v2.9.9.

Patches

We recommend all users upgrade to the latest version, v2.9.9, which includes the security fix.

References

- patch - releases

Acknowledgments

We would like to thank keomutchoiboi who reported this issue to us via our security email, security@projectdiscovery.io. We appreciate the responsible disclosure of this issue.

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 - Security Patch Pull Request: GitHub PR #4822 - Workflows Overview: Nuclei Workflows Documentation - Code Template Reference: Nuclei Code Protocols Documentation - Template Signing Reference: Nuclei Template Signing Documentation

Nuclei versions before 3.11.1 cache template signature verification based only on file modification time without content checksums. Attackers can replace verified templates with unsigned malicious content and restore the original modification time to bypass signature checks and execute arbitrary operating system commands.

A vulnerability in Nuclei's JavaScript protocol runtime allows JavaScript templates to read local .js and .json files through the require() function, bypassing the default local file access restriction.

Affected Component

The issue is in the JavaScript runtime's module loading system. The goja require() function used a default host filesystem loader without routing through the allow-local-file-access check.

Description

The goja require() function in Nuclei's JavaScript protocol runtime used the default host filesystem loader, which allowed JavaScript templates to import .js and .json files from anywhere on the host filesystem, ignoring the allow-local-file-access (-lfa) option that controls file access outside the template directory.

The impact is limited to .js and .json files, as goja's module loader only resolves those extensions. That said, this is still enough to expose sensitive data stored in JSON configuration files like package.json, credential stores, or cloud configuration files sitting on the host filesystem.

Affected Users

- CLI users running untrusted or third-party JavaScript templates. - SDK users who have integrated Nuclei into platforms where end-users can supply JavaScript templates, especially when relying on the default file access restriction to limit filesystem reads.

[!NOTE] The require() module loader only resolves .js and .json files. Other file types cannot be read through this vector.

Patches

- The vulnerability is fixed in Nuclei v3.8.0. Upgrading is strongly recommended. - Fix reference: #7332

Mitigation

Upgrade to Nuclei v3.8.0, where the require() registry is rebuilt per execution and file-backed module loads are routed through the same allow-local-file-access check as the rest of the filesystem operations.

In the meantime, avoid running JavaScript templates from unverified sources.

Workarounds

If upgrading is not an option, avoid running untrusted JavaScript templates entirely. There is no flag or configuration that mitigates this on affected versions.

Acknowledgments

Nuceli thanks @AkashHamal0x01 for reporting this issue through responsible disclosure via security@projectdiscovery.io

A vulnerability in Nuclei's expression evaluation engine makes it possible for a malicious target server to inject and execute supported DSL expressions. This happens when HTTP response data containing helper/function syntax gets reused by multi-step templates. If the -env-vars / -ev option is explicitly enabled, this can expose host environment variables. That option is off by default, so standard configurations are not affected by the information disclosure risk.

Affected Component

The issue lives in expressions.Evaluate() at pkg/protocols/common/expressions/ and in the unresolved-variable validation path (hasLiteralsOnly()).

Description

expressions.Evaluate() replaces placeholders first, then scans the substituted output for expressions. Because of this two-pass approach, response-derived values (including extractor output and response body content) can be reinterpreted as DSL/helper syntax on the second pass.

When -env-vars (-ev) is enabled, environment variables get merged into the template variable map. A malicious target can return response data containing expressions like {{envvarname}} which, when reused in a subsequent template request, resolve to actual environment variable values. This can expose sensitive host data like API keys, credentials, and tokens.

Without -ev enabled (the default), injected DSL expressions may still trigger helper functions such as {{md5("test")}}, but this has no meaningful security impact beyond unexpected behavior.

There is also a separate issue in hasLiteralsOnly(): it was evaluating helper expressions while deciding whether {{...}} contained unresolved variables, which caused validation logic to run side-effectful helpers even when the final request kept the value as a literal.

[!NOTE] The -env-vars / -ev option is off by default. Users who have not explicitly turned it on are not affected by the information disclosure aspect of this vulnerability.

Affected Users

- CLI users running multi-step templates (with extractors or flow-based request chaining) that reuse response-derived values against untrusted or attacker-controlled targets, with the -ev flag enabled. - SDK users who have integrated Nuclei into platforms where EnvironmentVariables is set to true and scan targets are not fully trusted.

Patches

- The vulnerability is fixed in Nuclei v3.8.0. Upgrading to this version is strongly recommended. - Relevant fix references: #7221, #7321.

Mitigation

Upgrade to Nuclei v3.8.0. The updated evaluation logic now collects expressions from the original template text before placeholder substitution and only evaluates those template-authored expressions.

If you have -ev enabled, disable it when scanning untrusted targets to avoid environment variable disclosure.

Workarounds

If upgrading is not an option right now, make sure -env-vars / -ev is not enabled when running multi-step templates against untrusted targets.

Acknowledgments

Nuclei thanks @gnuletik for reporting this issue through responsible disclosure via security@projectdiscovery.io