CVE-2025-2783
Google Chromium Mojo Sandbox Escape Vulnerability
Description
CVE-2025-2783 is a high-severity sandbox escape vulnerability in Google Chrome's Mojo IPC component on Windows. The flaw involves an incorrect handle being provided in unspecified circumstances, allowing a remote attacker to escape Chrome's security sandbox through a malicious file. With a CVSS v3.1 score of 8.3 and its addition to CISA's Known Exploited Vulnerabilities catalog with a remediation deadline of April 17, 2025, CVE-2025-2783 represents a significant threat as sandbox escapes are among the most valuable and difficult-to-achieve browser vulnerabilities. The EPSS score of 41.6% at the 97th percentile indicates very high exploitation probability, consistent with reports of this vulnerability being used in sophisticated targeted attacks.
KEV Information
CVSS Score
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:HOpen in CalculatorAffected Products
| Vendor | Product | Version |
|---|---|---|
| chrome | < 134.0.6998.177 |
References
- https://chromereleases.googleblog.com/2025/03/stable-channel-update-for-desktop_25.html(Release Notes)
- https://issues.chromium.org/issues/405143032(Permissions Required)
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-2783(US Government Resource)
Weakness Type
This CVE has no assigned CWE identifiers in the NVD database. The vulnerability involves incorrect handle management in Chrome's Mojo interprocess communication framework, which is a specialized component for managing communication between Chrome's sandboxed renderer processes and privileged broker processes. The incorrect handle allows a sandboxed process to gain access to resources outside the sandbox boundary.
Impact Analysis
CVE-2025-2783 carries a CVSS v3.1 score of 8.3 (High) with changed scope (S:C), indicating impact beyond the vulnerable component. The attack is network-accessible (AV:N) but requires high complexity (AC:H) and user interaction (UI:R) — the victim must interact with a malicious file, typically through visiting a compromised or attacker-controlled website. No privileges are required (PR:N). Confidentiality, integrity, and availability are all rated High with changed scope because a sandbox escape in Chrome effectively neutralizes the primary security boundary between web content and the underlying operating system. An attacker who escapes the Chrome sandbox gains the ability to execute arbitrary code with the full privileges of the Chrome browser process, access the user's filesystem, steal credentials, install malware, and potentially escalate further on the system. The EPSS score of 41.6% at the 97th percentile reflects the high value and active exploitation of this vulnerability, particularly in targeted attack campaigns where browser sandbox escapes are combined with renderer vulnerabilities for full exploit chains.
Exploit Maturity
CVE-2025-2783 demonstrates high exploit maturity, evidenced by its inclusion in CISA's Known Exploited Vulnerabilities catalog and its use in targeted attacks before the patch was released. The EPSS score of 41.6% at the 97th percentile indicates significant exploitation probability. The Chrome release notes confirm this was a zero-day vulnerability that was exploited in the wild before the fix in Chrome 134.0.6998.177. Sandbox escape vulnerabilities in Chrome are exceptionally rare and valuable, typically associated with nation-state threat actors and commercial spyware vendors. The Mojo IPC component is a critical security boundary in Chrome's architecture, and vulnerabilities in this component are among the most sought-after by advanced threat actors because they enable full system compromise when chained with a renderer exploit.
Remediation
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Update Google Chrome to version 134.0.6998.177 or later on all Windows systems immediately. This can be done through Chrome's built-in update mechanism (Menu > Help > About Google Chrome) or through enterprise deployment tools such as WSUS, SCCM, or Group Policy for managed environments.
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Verify Chrome auto-updates are functioning across all managed endpoints. Check that the Google Update service is running and not blocked by firewall rules or group policies. In enterprise environments, ensure the Chrome update infrastructure is distributing the patched version.
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Enable Chrome's Enhanced Safe Browsing to receive faster protection against newly discovered threats. This feature provides real-time URL checking and download scanning that can help detect exploitation attempts before the sandbox escape is triggered.
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Deploy browser isolation solutions for high-risk users (executives, finance, IT administrators) who are likely targets of sophisticated attacks. Browser isolation renders web content in a remote environment, adding an additional security boundary even if the local browser is compromised.
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Monitor endpoints for indicators of compromise associated with Chrome exploitation, including unexpected child processes spawned by chrome.exe, unusual DLL loading patterns, and suspicious network connections originating from the Chrome process. Endpoint detection and response (EDR) tools should be configured to alert on sandbox escape indicators.
Technical Details
CVE-2025-2783 is a sandbox escape vulnerability in Chrome's Mojo IPC (Inter-Process Communication) framework on Windows, fixed in Chrome 134.0.6998.177. The CVSS v3.1 vector CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:H indicates a network-accessible attack requiring user interaction (visiting a malicious page or opening a malicious file) with changed scope. Chrome's multi-process architecture relies on Mojo for communication between sandboxed renderer processes and the privileged browser process. Each process operates with different privilege levels, and the sandbox restricts renderer processes from accessing operating system resources directly. The vulnerability occurs when an incorrect handle is provided during IPC operations, allowing a sandboxed process to obtain a handle to a resource that should only be accessible to the privileged browser process. With this escaped handle, the attacker can interact with OS resources outside the sandbox boundary. On Windows, handles are kernel objects that grant access to system resources, and obtaining an incorrectly scoped handle effectively bypasses the entire sandbox security model. The specific circumstances that trigger the incorrect handle provision are not fully disclosed to prevent additional exploitation.
Frequently Asked Questions
Is CVE-2025-2783 being actively exploited?
Yes. CVE-2025-2783 was exploited as a zero-day vulnerability before the Chrome 134.0.6998.177 patch was released. CISA has confirmed active exploitation by adding it to the KEV catalog. The attack was used in sophisticated targeted campaigns.
What products are affected by CVE-2025-2783?
Google Chrome on Windows prior to version 134.0.6998.177 is affected. Other Chromium-based browsers on Windows (Microsoft Edge, Brave, Opera) may also be affected if they use vulnerable Mojo IPC code and have not been updated.
How do I fix CVE-2025-2783?
Update Google Chrome to version 134.0.6998.177 or later. Chrome typically updates automatically, but you should verify the update has been applied, especially in enterprise environments where auto-updates may be delayed.
How severe is CVE-2025-2783?
CVE-2025-2783 has a CVSS score of 8.3 (High) with changed scope. Sandbox escapes are among the most severe browser vulnerabilities because they break the primary security boundary between web content and the operating system. The EPSS score of 41.6% confirms very high exploitation probability.
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