cbcvebase.
CVE-2018-4317
published 2019-04-03

CVE-2018-4317: 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
9.35%
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

otherWebCore::RenderLayer::updateDescendantDependentFlags
  • The UAF is triggered inside WebCore::RenderLayer::updateDescendantDependentFlags during layout processing; monitor for crashes or heap-use-after-free ASan reports originating from this function in WebKit/WebCore.
  • The freed object is a WebCore::RenderLayerModelObject; the free occurs in RenderLayerModelObject::willBeDestroyed() while a dangling pointer is still reachable via the render layer tree traversal.
  • The exploit PoC uses malformed/invalid CSS properties (e.g., -webkit-column-count, display:contents, transform-style, -webkit-text-orientation combined with syntax errors) to trigger the layout path leading to the UAF; web content containing such malformed CSS targeting WebKit should be treated as suspicious.
  • The vulnerability is reachable via processing maliciously crafted web content in WebKit across iOS, tvOS, Safari, iTunes for Windows, and iCloud for Windows; any WebKit-based browser/app on unpatched versions (prior to iOS 12, tvOS 12, Safari 12, iTunes 12.9, iCloud for Windows 7.7) is at risk.
  • ·The freed memory region is 320 bytes, with the use-after-free access occurring 50 bytes inside the region; this heap layout detail may vary across builds and allocator states.

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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