CVE-2016-5198
Google Chromium V8 Out-of-Bounds Memory Vulnerability
Description
CVE-2016-5198 is an out-of-bounds memory access vulnerability in the Google Chromium V8 JavaScript engine that allows a remote attacker to perform unauthorized read and write operations, leading to code execution via a crafted HTML page. The flaw enables an attacker to access memory beyond the intended boundaries of a buffer, providing both information disclosure and the ability to corrupt heap structures for arbitrary code execution. This Chromium V8 vulnerability affects multiple web browsers including Google Chrome, Microsoft Edge, and Opera. CISA has added CVE-2016-5198 to its Known Exploited Vulnerabilities catalog, and with an EPSS score of 77.9% (98th percentile), this vulnerability poses a critical threat to browser security.
KEV Information
CVSS Score
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:HOpen in CalculatorAffected Products
| Vendor | Product | Version |
|---|---|---|
| chrome | < 54.0.2840.90; < 54.0.2840.85; < 54.0.2840.87 | |
| redhat | enterprise linux desktop | 6.0 |
| redhat | enterprise linux server | 6.0 |
| redhat | enterprise linux workstation | 6.0 |
Multiple CVSS Assessments
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
References
- http://rhn.redhat.com/errata/RHSA-2016-2672.html(Third Party Advisory)
- http://www.securityfocus.com/bid/94079(Broken Link, Third Party Advisory, VDB Entry)
- http://www.securitytracker.com/id/1037224(Broken Link, Third Party Advisory, VDB Entry)
- https://chromereleases.googleblog.com/2016/11/stable-channel-update-for-desktop.html(Release Notes, Vendor Advisory)
- https://crbug.com/659475(Exploit, Issue Tracking)
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2016-5198(US Government Resource)
Weakness Type
CWE-787: Out-of-bounds Write
CVE-2016-5198 exploits an out-of-bounds memory access vulnerability in the Chromium V8 engine that enables both unauthorized reads and writes beyond buffer boundaries. The V8 engine fails to properly validate memory accesses during JavaScript execution, allowing an attacker to read sensitive data from adjacent memory regions and write malicious data to corrupt control structures, ultimately achieving arbitrary code execution within the browser process.
Learn more: CWE-787 — Out-of-bounds Write
Impact Analysis
CVE-2016-5198 is a critical vulnerability in the Chromium V8 JavaScript engine that enables both out-of-bounds read and write operations, making it particularly powerful as an exploit primitive. The vulnerability is remotely exploitable through a crafted web page with no authentication required and low attack complexity. Confidentiality is critically impacted as the out-of-bounds read capability allows an attacker to leak sensitive data from V8 heap memory, including object addresses useful for bypassing ASLR. Integrity is critically impacted as the out-of-bounds write enables memory corruption for code execution. The combined read/write primitive makes this vulnerability significantly more exploitable than a pure write vulnerability, as the attacker can first leak memory layout information before performing targeted corruption. The EPSS score of 77.9% (98th percentile) indicates very high exploitation probability, and the vulnerability's impact extends across all Chromium-based browsers.
Exploit Maturity
CISA has confirmed active exploitation of CVE-2016-5198 by including it in the Known Exploited Vulnerabilities catalog, with a remediation deadline of June 22, 2022. The EPSS score of 77.9% (98th percentile) reflects very high exploitation probability. No specific ransomware campaigns have been publicly attributed to this vulnerability. However, the combined read/write nature of this out-of-bounds access makes it an especially valuable exploit primitive. V8 vulnerabilities providing both information leakage and memory corruption are considered top-tier by exploit developers, as they enable building complete exploit chains within a single vulnerability — reading memory layout to bypass ASLR and then writing to corrupt control flow data.
Remediation
- Update all Chromium-based browsers immediately to versions that patch CVE-2016-5198, including Google Chrome, Microsoft Edge, Opera, and other Chromium-derived browsers.
- Enable automatic browser updates on all managed endpoints to ensure timely application of V8 security patches.
- Deploy browser isolation technology to execute untrusted web content in isolated environments, preventing V8 out-of-bounds access exploits from affecting the local system.
- Implement web proxy filtering to block access to known malicious domains and suspicious content that may serve as exploit delivery vectors.
- Monitor endpoint detection systems for browser exploitation activity including V8 renderer crashes, unusual memory access patterns, or unexpected process spawning from browser processes that may indicate exploitation of this or similar V8 vulnerabilities.
Technical Details
CVE-2016-5198 is an out-of-bounds memory access vulnerability in the V8 JavaScript engine used by Chromium-based browsers that uniquely provides both read and write primitives from a single flaw. The vulnerability occurs when V8 processes crafted JavaScript that triggers a code path where memory access bounds are not properly validated, allowing the engine to read from and write to memory locations beyond the intended buffer boundaries. The out-of-bounds read component enables an attacker to leak V8 heap layout information, including object addresses and pointer values, which is essential for constructing reliable exploits in the presence of ASLR. The out-of-bounds write component then allows the attacker to corrupt adjacent heap objects, overwriting function pointers, array lengths, or typed array backing store pointers to achieve arbitrary read/write over the entire process memory space. This escalation from bounded out-of-bounds access to arbitrary memory manipulation is a well-documented V8 exploitation technique that culminates in code execution within the renderer process.
Frequently Asked Questions
Is CVE-2016-5198 being actively exploited?
Yes. CISA has added CVE-2016-5198 to its Known Exploited Vulnerabilities catalog, confirming active exploitation in the wild. The EPSS score of 77.9% (98th percentile) indicates very high exploitation probability. The combined read/write nature of this vulnerability makes it especially valuable to exploit developers.
What products are affected by CVE-2016-5198?
CVE-2016-5198 affects all Chromium-based browsers including Google Chrome, Microsoft Edge, Opera, Brave, and Vivaldi. Any browser using the affected V8 engine version is vulnerable when processing a crafted HTML page.
How do I fix CVE-2016-5198?
Update all Chromium-based browsers to the latest patched versions. Enable automatic browser updates on all managed devices and deploy browser isolation technology for defense-in-depth against V8 vulnerabilities.
How severe is CVE-2016-5198?
CVE-2016-5198 is a critical out-of-bounds memory access vulnerability with an EPSS score of 77.9% in the 98th percentile. Unlike many memory corruption bugs, it provides both read and write capabilities, enabling complete exploitation from a single vulnerability — information leakage to bypass ASLR followed by targeted memory corruption for code execution.
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