External risk intelligence

Module::Load Arbitrary Module Load Vulnerability

CVE advisorySeverity: CRITICAL (CVSS 9.8)

CVE-2011-10043

This vulnerability exists in a Perl module library used during application development and execution. It is a build-time or internal component dependency rather than a standalone internet-facing service, gateway, or edge application. Public exposure of this specific code execution path requires an attacker to already control input to the application's internal module-loading logic.

Halo Surface Signal: 1 out of 5 — much less likely to be public-facing.

External exposure likelihood

Horizon Alert

Summary of the vulnerability and why it matters

A vulnerability in a Perl module could allow attackers to execute arbitrary code by manipulating module names. This could lead to significant compromise if attackers can influence the affected module loading process. The main concern is confirming relevance and exposure within our development and execution environments.

Code execution via module loading manipulation.
Potential for significant system compromise.
Confirm relevance and exposure internally.

Attack Path

How an attacker could exploit the issue

An attacker could exploit this vulnerability if they can influence how a Perl application loads modules. By crafting a module name that starts with "::", they can trick the application into loading an arbitrary module from any location, potentially leading to the execution of their own code. This could occur if an application uses a vulnerable version of the Module::Load library and allows user input to directly affect module names.

Attacker influences module loading.
Crafted module name triggers loading.
Risk of arbitrary code execution.

Live Threat

Current exploitation, exposure, and threat context

Module::Load versions before 0.22 for Perl allow arbitrary modules outside of @INC to be loaded. When supported by the advisory, attackers able to influence module names passed to the load function could use this vulnerability to specify arbitrary module paths and potentially execute arbitrary code.

Arbitrary code execution.
Uncontrolled module loading via name manipulation.
System compromise or data exposure.

Operational Fix

Recommended remediation, mitigation, and detection steps

This vulnerability in a Perl module library impacts applications that dynamically load modules. Application owners and development teams are primarily responsible for addressing this, with support from infrastructure or platform teams to manage the Perl environment. The initial step involves identifying all applications utilizing this module, assessing their exposure, and prioritizing remediation based on business criticality and reachability.

Application owners to manage the issue.
Verify affected Perl applications and usage.
Plan remediation during maintenance windows.

Supplementary metadata

CVSS vector

Validate whether this threat affects your internet-facing exposure.

Halo Threat Intelligence helps prioritize remediation with Halo Surface Signal and H/A/L/O context. Start exposure validation with a free external attack surface trial.

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Frequently asked questions

What is Module::Load and why is it used?

Module::Load is a Perl module library that simplifies the process of dynamically loading other code libraries into an application at runtime. Developers use it to keep their software modular, allowing programs to pull in necessary functions or features only when required during execution rather than loading everything at startup.

How does CVE-2011-10043 allow arbitrary code execution?

This vulnerability is classified under CWE-145. It occurs because the library does not properly sanitize module names passed to its loading function. If an attacker provides a name starting with '::', the software may interpret it as a path, allowing it to load and execute unauthorized files located outside the intended directories, effectively running the attacker's code.

Do I need to worry about any module name causing this?

No. The flaw specifically requires an attacker to successfully manipulate the input provided to the module-loading function. If your application logic does not allow user input or external data to determine which modules are loaded, this specific trigger path is not available for exploitation.

Is my internal Perl application at risk from this CVE?

According to Halo Surface Signal, this vulnerability is a build-time or internal component dependency, making it very unlikely to be an internet-facing entry point. While it is not a standalone gateway, you should check if your application's internal logic allows untrusted users to influence module-loading decisions, as that is the primary requirement for a successful attack.

When should I update my Perl environment?

You should prioritize updating Module::Load to version 0.22 or later if you identify applications that dynamically load modules using user-supplied input. Start by creating an inventory of all projects using this library and coordinate with development teams to apply the update during your next scheduled maintenance window.

References

Written by Nicholas Merritt

Nicholas Merritt is VP of Security Solutions at Halo Security. With more than 25 years across application security, vulnerability prioritization, and offensive security, he helps teams translate threat data into practical exposure validation and remediation focus. He authors Halo Threat Intelligence CVE advisories using Halo Surface Signal and H/A/L/O context to prioritize internet-facing risk.