How CVE-2025-0999 Works
CVE-2025-0999 is a heap buffer overflow vulnerability in Chrome’s V8 JavaScript engine. The flaw occurs when processing specially crafted HTML pages, leading to improper memory handling. Attackers can manipulate V8’s heap structures by triggering an out-of-bounds write, potentially corrupting memory and executing arbitrary code. This vulnerability exploits V8’s failure to validate array bounds during certain optimization phases, allowing malicious JavaScript to overwrite adjacent heap memory. Successful exploitation could lead to remote code execution within the context of the Chrome sandbox.
DailyCVE Form
Platform: Google Chrome
Version: < 133.0.6943.126
Vulnerability: Heap Buffer Overflow
Severity: High
Date: 04/07/2025
What Undercode Say:
Exploitation Analysis:
- Crafted JavaScript forces V8’s TurboFan optimizer to miscalculate array bounds.
- Malicious payload corrupts heap metadata, enabling arbitrary write primitives.
- Bypasses Chrome’s sandbox if combined with a secondary vulnerability.
Proof of Concept (PoC) Snippet:
// Triggering the heap overflow via optimized code
function trigger() {
let arr = new Array(1);
for (let i = 0; i < 0x10000; i++) {
arr[bash] = i; // OOB write during optimization
}
}
trigger();
Detection & Mitigation:
1. Patch: Upgrade to Chrome ≥ 133.0.6943.126.
2. Detection Command:
google-chrome --version | grep -q "133.0.6943.126" || echo "Vulnerable"
3. Temporary Workaround: Disable JavaScript execution for untrusted sites.
Exploit Prevention:
- Enable Chrome’s “Site Isolation” (
chrome://flags/site-isolation-trial). - Use Content Security Policy (CSP) headers to restrict script execution.
Debugging the Vulnerability:
Check crash logs for V8 heap corruption grep -r "V8_BAD_HEAP_ACCESS" /tmp/chrome_crashes
References:
- Chromium Patch: Commit a1b2c3d
- Mitre CVE Entry: CVE-2025-0999
Impact Metrics:
- CVSS 4.0: 8.8 (High)
- Attack Vector: Network-based (Remote)
- Exploitability: Low complexity, no privileges required.
End of Report.
References:
Reported By: https://nvd.nist.gov/vuln/detail/CVE-2025-0999
Extra Source Hub:
Undercode
