External risk intelligence

Apache HTTP Server: URL Mapping Vulnerability Allows Code Execution

CVE advisoryKnown Exploit

CVE-2024-38475

A flaw in Apache HTTP Server's mod_rewrite allows attackers to map URLs to unintended filesystem locations, potentially leading to code execution or source code disclosure. This poses a business risk through unauthorized access and sensitive data exposure.

5Halo Surface Signal

Apache Http Server

2.4.0 to before 2.4.60before 10.2.1.14-75sv

External exposure likelihood

Halo Surface Signal score for CVE-2024-38475

The vulnerability exists in Apache HTTP Server, a foundational component widely deployed as a public-facing web server and gateway to handle incoming internet traffic. Its primary function is to listen for and process external requests, making this service inherently reachable from the internet in common deployment patterns.

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Horizon Alert

Summary of the vulnerability and why it matters

The Apache HTTP Server's mod_rewrite component has a flaw that allows attackers to access files on the filesystem not intended for public access. This could lead to the disclosure of sensitive source code or the execution of malicious code. The vulnerability stems from how the server handles certain URL mappings.

  • Vulnerable: Apache HTTP Server mod_rewrite
  • Flaw: Improper output escaping
  • Impact: Code execution or source code disclosure

Attack Path

How an attacker could exploit the issue

A vulnerability in Apache HTTP Server's mod_rewrite can allow an attacker to map URLs to unintended filesystem locations. This could lead to the execution of malicious code or the exposure of source code. This occurs when specific server context substitutions involve backreferences or variables as the first segment.

  • Exposure to the network.
  • Attacker gains unauthorized access.
  • Triggering URL mapping for control.

Live Threat

Current exploitation, exposure, and threat context

The Apache HTTP Server has a critical vulnerability that could allow attackers to execute code or disclose source code. This could happen by mapping URLs to unintended filesystem locations. The impact includes potential system compromise and sensitive data exposure. Organizations should treat this as a high-priority issue.

  • Attackers with no special skill needed.
  • No authentication or access required.
  • High risk; treat as urgent.

Priority actions

Operational Fix

Recommended remediation, mitigation, and detection steps

This vulnerability in Apache HTTP Server can allow an attacker to map URLs to unintended filesystem locations, potentially leading to code execution or source code disclosure. The attack vector is external, meaning it can be exploited over the network. Affected organizations should prioritize identifying and securing exposed systems to mitigate business risk.

  • Find all affected Apache HTTP Server instances.
  • Reduce exposure or isolate risk.
  • Apply vendor fixes and validate.
  • Monitor for related issues.

Frequently asked questions

What is Apache HTTP Server and what is it used for?

Apache HTTP Server is a widely used, open-source web server software. It is fundamental for making websites and online applications accessible on the internet by handling requests from web browsers and serving the corresponding content. It is often deployed as a public-facing gateway to manage incoming internet traffic.

How does CVE-2024-38475 allow for code execution?

CVE-2024-38475 is a weakness classified as CWE-116, improper escaping of output. In Apache HTTP Server's mod_rewrite, this flaw allows an attacker to craft specific URLs. When processed, these URLs can be mapped to filesystem locations that the server is permitted to access but were not intended to be directly reachable, potentially leading to code execution or disclosure of source code.

What actions do not trigger the Apache HTTP Server vulnerability?

The vulnerability is triggered by specific substitutions in the server context within mod_rewrite that use backreferences or variables as the first segment of the substitution. Substitutions that do not follow this pattern are not affected by this particular improper escaping of output flaw.

Why should I care about CVE-2024-38475 if my systems are internet-facing?

This vulnerability affects systems that are internet-facing, meaning they are directly accessible from the public internet. Given its nature, it can be exploited remotely without requiring authentication or special privileges, posing a significant risk to organizations that host services using the affected Apache HTTP Server versions.

What is the first step for managing this Apache HTTP Server threat?

The initial step is to identify all instances of the Apache HTTP Server within your environment that are running version 2.4.59 or earlier. Once identified, you should prioritize reducing their exposure, isolating any high-risk systems, and applying the vendor-provided fixes as soon as possible.

References

Sources and related resources

Primary sources: NVD, CVE.org, CISA KEV.

NVDPublished Modified