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CivetWeb Vulnerabilities Expose Ubuntu LTS Systems to Remote Attacks

Critical flaws in CivetWeb affect Ubuntu 22.04 and 24.04 LTS, potentially enabling denial of service or remote code execution.

TL;DR

  • Two high-severity vulnerabilities found in CivetWeb library impact Ubuntu LTS versions 22.04 and 24.04.
  • CVE-2025-55763 allows potential remote code execution through URI parsing errors.
  • CVE-2025-9648 can lead to denial of service via malformed HTTP request handling.
  • Systems using CivetWeb on affected Ubuntu versions should apply updates immediately.
  • These issues highlight risks in embedded web server libraries used across applications.

A recent Ubuntu Security Notice has flagged multiple critical vulnerabilities in CivetWeb, a lightweight web server library commonly used in embedded systems and applications. These flaws pose significant risk to systems running Ubuntu 22.04 and 24.04 LTS, where improper URI and HTTP request parsing could allow attackers to crash services or execute arbitrary code remotely.

Organizations relying on software that integrates CivetWeb should prioritize patching efforts. The vulnerabilities underscore the importance of monitoring third-party components for security updates, especially those exposed to untrusted network inputs. Immediate remediation is advised to prevent exploitation.

Vulnerability Details

  • CVE-2025-55763 involves incorrect URI parsing that may result in buffer overflows, allowing remote code execution.
  • CVE-2025-9648 affects how CivetWeb processes specific HTTP requests, which can trigger crashes leading to denial of service.
  • Both vulnerabilities are exploitable over the network without authentication, increasing their severity.
  • Only Ubuntu 22.04 LTS and Ubuntu 24.04 LTS releases are impacted by these issues.

Impact and Mitigation

  • Affected systems should upgrade CivetWeb to the latest patched version provided by Ubuntu.
  • Developers using CivetWeb directly should audit their implementations for exposure to external input.
  • Organizations should review dependencies in build environments and container images for vulnerable versions.
  • Monitoring for unusual service disruptions or unexpected behavior can help detect possible exploitation attempts.

Sources

Sources

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