cbcvebase.
CVE-2018-4197
published 2019-04-03

CVE-2018-4197: A use after free issue was addressed with improved memory management. This issue affected versions prior to iOS 12, tvOS 12, Safari 12, iTunes 12.9 for…

PriorityP261high8.8CVSS 3.0
AVNACLPRNUIRSUCHIHAH
EXPLOIT
EPSS
9.39%
94.9th percentile
A use after free issue was addressed with improved memory management. This issue affected versions prior to iOS 12, tvOS 12, Safari 12, iTunes 12.9 for Windows, iCloud for Windows 7.7.

Affected

11 ranges
VendorProductVersion rangeFixed in
appleicloud< 7.77.7
appleicloud_for_windows
appleios
appleiphone_os< 12.012.0
appleitunes< 12.912.9
appleitunes_12.9_for_windows
applesafari< 1212
applesafari
appletvos< 1212
appletvos
debianwebkit2gtk< webkit2gtk 2.22.0-2 (bookworm)webkit2gtk 2.22.0-2 (bookworm)

Detection & IOCsextracted from sources · hover to see the quote

commanddocument.execCommand("selectAll", false)
commandvar00140.deleteFromDocument()
  • The UAF is triggered via a specific sequence: appending a child node to a DOM element, calling window.getSelection(), executing 'selectAll' via document.execCommand(), then calling deleteFromDocument() on the selection — all within a window onload handler.
  • The crash originates in WebCore::RenderTreeBuilder::removeAnonymousWrappersForInlineChildrenIfNeeded — monitor WebContent process crashes in WebCore at this symbol as a UAF indicator.
  • The exploit uses CSS property -webkit-column-count combined with float:left on pseudo-elements (::selection, ::first-letter) and focus selectors to set up the render tree state required for the UAF.
  • Maliciously crafted web content triggering arbitrary code execution via WebKit affects iOS < 12, tvOS < 12, Safari < 12, iTunes < 12.9 for Windows, and iCloud for Windows < 7.7 — flag WebKit-based browsers on these versions processing untrusted content.
  • ·The exploit PoC uses a fuzzer-generated HTML/JS structure; real-world exploits may vary the specific DOM manipulation sequence while preserving the core trigger (selectAll + deleteFromDocument on a manipulated render tree).

CVSS provenance

nvdv3.08.8HIGHCVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
nvdv2.06.8MEDIUMAV:N/AC:M/Au:N/C:P/I:P/A:P
osv8.8HIGH
vendor_debian8.8LOW
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