CVE-2025-30360

What it actually does

This is an information disclosure vulnerability that can allow source code accessible from a vulnerable Ubuntu Pro 14.04 LTS linux-azure system to be exposed when a user visits a malicious website using a non-Chromium-based browser. Based on the available advisory details, the flaw does not indicate remote code execution or privilege escalation; the primary risk is unauthorized reading or theft of sensitive local content, particularly source code reachable by the affected user context.

Why it matters to the business

Successful exploitation could result in theft of proprietary source code, embedded secrets, intellectual property, or implementation details that help attackers plan follow-on attacks. The risk is most relevant for developer workstations, build systems, or administrative hosts where source repositories are present and web browsing is possible. The vulnerability is not listed in CISA KEV, is not known to be used in ransomware campaigns, and has a low EPSS score, so broad active exploitation is not currently indicated; however, exposure should still be remediated where affected Ubuntu Pro 14.04 LTS linux-azure kernels remain in use.

How an attack unfolds

An attacker would first host or compromise a website containing content designed to trigger the information disclosure condition. The attacker then persuades a user on an affected Ubuntu Pro 14.04 LTS linux-azure system to visit that site using a non-Chromium-based browser. If the vulnerable component is present and the browser interaction reaches the vulnerable code path, content accessible to the user session, such as local source code or related files, may be exposed to the malicious page or exfiltrated over the network. The attacker can then review the stolen code for secrets, credentials, business logic, or additional vulnerabilities. No public exploit maturity or known KEV exploitation is indicated from the provided data.

How to fix it

Upgrade the affected Ubuntu Pro 14.04 LTS linux-azure package to the fixed version: linux-azure 4.15.0-1168.183~14.04.1 or later. After installing the updated kernel/package, reboot systems as required so the fixed kernel is active. Where immediate patching is not possible, reduce exposure by preventing general web browsing from systems that contain source code, restricting use of non-Chromium-based browsers on affected hosts, isolating developer/build environments from untrusted web access, and ensuring source repositories do not contain plaintext secrets. Because Ubuntu 14.04 is an extended-support platform, also consider lifecycle migration planning to a currently supported operating system release.

How to confirm the fix worked

Confirm package remediation by checking that the installed linux-azure package version is 4.15.0-1168.183~14.04.1 or later. On Debian/Ubuntu-based systems, use package inventory tools such as dpkg-query, apt-cache policy, unattended-upgrades logs, or vulnerability management scans to verify the installed version. Confirm the running kernel after reboot with uname -r and ensure it corresponds to the updated linux-azure package. Validate exposure reduction by confirming that affected systems are not used for untrusted web browsing, especially with non-Chromium-based browsers, and that endpoint controls restrict browser access to sensitive source directories where practical.

Typical attack path

1. Identify organizations or users likely to have source code on Ubuntu Pro 14.04 LTS linux-azure systems.
2. Prepare a malicious website that triggers the information disclosure behavior when accessed with a non-Chromium-based browser.
3. Deliver the lure through phishing, social media, developer forums, compromised websites, or watering-hole placement.
4. Wait for a vulnerable user to visit the site from an affected system and browser combination.
5. Cause the browser session to expose or transmit accessible source code or related local content.
6. Exfiltrate the disclosed data to attacker-controlled infrastructure.
7. Analyze stolen code for secrets, intellectual property, or weaknesses useful for follow-on compromise.

How to detect it

To assess whether exploitation may already have occurred, review web proxy, secure web gateway, DNS, browser history, and endpoint telemetry from affected systems for visits to suspicious or newly registered domains, especially where followed by outbound POST, PUT, WebSocket, or large HTTPS transfers. Correlate browser processes such as Firefox or other non-Chromium-based browsers with file access to source repositories, build directories, project workspaces, .git metadata, SSH keys, API tokens, or credential files. Examine endpoint detection logs for unusual browser file reads followed by network connections to unfamiliar destinations. Review browser crash reports, system logs, and auditd/file integrity telemetry around the time of suspicious browsing. Because no specific public exploit artifact, payload string, or attacker infrastructure is provided, detection should rely on behavioral correlation rather than fixed signatures.

What your security team should do

• Inventory Ubuntu Pro 14.04 LTS linux-azure systems and identify any running linux-azure versions older than 4.15.0-1168.183~14.04.1.
• Prioritize remediation for developer workstations, build servers, CI/CD hosts, and administrative systems where source code or secrets may be present.
• Patch affected systems to linux-azure 4.15.0-1168.183~14.04.1 or later and reboot to activate the fixed kernel.
• Temporarily restrict non-Chromium-based browser use on unpatched systems that store or access source code.
• Review source repositories for embedded credentials, tokens, private keys, or other secrets that would increase impact if code was disclosed.
• Monitor web proxy, DNS, browser, and endpoint telemetry for suspicious browsing followed by unusual outbound uploads from developer or build systems.
• Plan migration away from legacy Ubuntu 14.04 systems where operationally feasible to reduce long-term patching and exposure risk.