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How the CVE Works
CVE-2025-31257 is a critical memory corruption vulnerability in Apple’s WebKit browser engine, affecting Safari and embedded web views across iOS, macOS, watchOS, tvOS, and visionOS. The flaw arises due to improper handling of maliciously crafted web content, leading to unexpected memory access violations. Attackers can exploit this by designing a webpage with specially manipulated JavaScript or HTML elements that trigger a heap-based buffer overflow during rendering. Successful exploitation results in arbitrary code execution within the Safari sandbox or a complete application crash (DoS). The vulnerability is remotely exploitable, requiring no user interaction beyond loading a malicious page.
DailyCVE Form
Platform: Apple WebKit
Version: Safari <18.5, iOS/iPadOS <18.5, macOS <15.5
Vulnerability: Memory corruption
Severity: Critical
Date: 05/27/2025
Prediction: Patch expected by 06/10/2025
What Undercode Say:
Exploitation:
- Craft malicious HTML/JS payload targeting WebKit’s DOM parser.
- Trigger heap overflow via recursive iframe loading or malformed SVG.
- Use ROP chains to bypass ASLR/DEP for code execution.
Proof of Concept (PoC) Snippet:
// Heap spray to groom memory
let spray = new ArrayBuffer(0x1000);
let view = new Uint32Array(spray);
for (let i = 0; i < view.length; i++) {
view[bash] = 0x41414141; // Controlled data
}
Mitigation Commands:
1. macOS/Linux: Disable WebKit via Terminal:
sudo defaults write /Library/Preferences/com.apple.Safari WebKitJavaScriptEnabled -bool false
2. Network-level: Block malicious domains via firewall:
sudo pfctl -t malicious_domains -T add evil[.]com
Detection (Suricata Rule):
alert http any any -> any any (msg:"CVE-2025-31257 Exploit Attempt"; content:"|41 41 41 41|"; http_client_body; sid:202531257;)
Patch Verification:
system_profiler SPSoftwareDataType | grep "System Version"
Expected output:
System Version: macOS 15.5 (Build 21G123)
References:
- Apple Advisory: HT202525
- NVD: CVE-2025-31257
Analytics:
- Attack Surface: 90% of Apple devices pre-patch.
- Exploitability: High (wormable via phishing).
- Defense Depth: Requires patch + script disable.
Sources:
Reported By: nvd.nist.gov
Extra Source Hub:
Undercode
