CVE-2025-24201

CVE-2025-24201 is an out-of-bounds write (CWE-787) in WebKit, the web rendering engine used across Apple's platforms, which Apple addressed with improved bounds checks. It is triggered by processing maliciously crafted web content, meaning a victim only has to load attacker-controlled web content in Safari or in any app that renders web content. A successful attacker can break out of the Web Content sandbox and perform unauthorized actions, an impact CISA scores at CVSS 10.0 (critical, scope-changing). Affected users include anyone running vulnerable versions of iOS, iPadOS, macOS Sequoia, Safari, visionOS, or watchOS; Debian Linux is also listed in the CPE data because Debian ships WebKit in its webkit packages. Apple reports the flaw may have been exploited in an extremely sophisticated attack against specific targeted individuals on versions of iOS before iOS 17.2 (this patch is a supplementary fix for that previously blocked attack, extended to older branches), and the CVE was added to CISA's KEV catalog on 2025-03-13.

What to do: Apply the vendor fixes immediately: Safari 18.3.1; iOS/iPadOS 18.3.2 (or 17.7.6, 16.7.11, or 15.8.4 on devices that cannot run the newest release); macOS Sequoia 15.3.2; visionOS 2.3.2; watchOS 11.4; and updated Debian webkit packages per Debian advisories. Because the CVE is in CISA's KEV catalog (added 2025-03-13), US federal agencies must patch per BOD 22-01, and all defenders should prioritize fleets with high-risk or frequently targeted users. Given the 'extremely sophisticated' targeted exploitation against individuals on iOS before 17.2, check whether targeted or high-value users' devices show indicators of compromise and ensure they are not left on older branches.