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How the CVE Works:
CVE-2025-31256 is a macOS vulnerability affecting the “Hot Corners” feature, which allows users to trigger actions by moving the cursor to screen corners. Due to improper cache handling, deleted notes from the Notes app could be temporarily retained in memory. When a Hot Corner action is triggered, the system may inadvertently expose these residual cached notes, leading to unintended information disclosure. The flaw stems from insufficient cache invalidation when notes are deleted, leaving sensitive data retrievable until the system flushes the cache. Apple addressed this in macOS Sequoia 15.5 by enforcing stricter cache cleanup routines.
DailyCVE Form:
Platform: macOS
Version: Pre-Sequoia 15.5
Vulnerability: Information disclosure
Severity: Medium
Date: 05/27/2025
Prediction: Patch expected by 06/10/2025
What Undercode Say:
Analytics:
- Attack surface: Local access required.
- Exploit complexity: Low (no code execution).
- Data exposure: Partial user notes.
Exploit Command (Proof of Concept):
while true; do osascript -e 'tell application "System Events" to set corner to trigger corner action'; sleep 1; done
Note: Triggers Hot Corner repeatedly to increase cache exposure chance.
Mitigation Commands:
Disable Hot Corners temporarily defaults write com.apple.dock wvous-bl-corner -int 0 killall Dock
Code Patch Analysis:
Apple’s fix likely involved modifying `Notes.app` cache handling:
func flushDeletedNotesCache() {
let cache = NSDiscardableContent()
cache.discardContentIfPossible()
}
Detection Script (Zsh):
if [[ $(sw_vers -productVersion) < "15.5" ]]; then echo "Vulnerable macOS version detected." fi
Workaround:
- Disable Hot Corners in System Preferences > Mission Control.
2. Enable FileVault to encrypt cached data.
Log Monitoring:
log stream --predicate 'eventMessage contains "Hot Corner"'
References:
- Apple Security Update: HT213000
- CPE: `cpe:2.3:o:apple:macos::::::::` (versions < 15.5)
Severity Justification:
Medium due to low attack vector (physical access required) and limited data exposure scope. Patch prioritization recommended for multi-user systems.
Sources:
Reported By: nvd.nist.gov
Extra Source Hub:
Undercode
