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HighCISA KEVExploited in the wildPublic exploit

Apple Multiple Products Integer Overflow or Wraparound Vulnerability

IdentifiersCVE-2021-30952CWE-190· Integer Overflow or WraparoundAlso known asbuffout

CVE-2021-30952 is an integer overflow vulnerability in Apple WebContent/WebKit processing that affects multiple Apple platforms. Apple states the issue was addressed with improved input validation and that processing maliciously crafted web content may lead to arbitrary code execution. The flaw was fixed in tvOS 15.2, macOS Monterey 12.1, Safari 15.2, iOS 15.2 and iPadOS 15.2, and watchOS 8.3. Reporting in the provided context also associates this CVE with the Coruna exploit kit under the codename "buffout," where it is described as a WebContent read/write exploit used against older iOS versions, particularly up to iOS 15.1.1.

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ANALYST BRIEF

Impact, mitigation & remediation

What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.

Impact

What an attacker gets, and what they’ve been doing with it.

Successful exploitation can result in arbitrary code execution in the context of web content processing on affected Apple devices. In practical terms, a victim visiting attacker-controlled or otherwise maliciously crafted web content could have code executed on the device, enabling compromise of the browser/WebContent process and potentially serving as an entry point into broader exploit chains such as those described for Coruna.

Mitigation

If you can’t patch tonight, do this now.

If immediate patching is not possible, reduce exposure to untrusted web content and restrict access to potentially malicious sites. Because exploitation is triggered through crafted web content, temporary mitigations include limiting Safari/WebKit exposure, using browser and device protections that block known malicious domains, and enabling Apple Lockdown Mode where available; the supplied context states Lockdown Mode blocks Coruna-related attacks. These are compensating controls only and do not replace patching.

Remediation

Patch, then assume compromise.

Apply Apple security updates that include the fix for CVE-2021-30952. The provided content states the issue is fixed in tvOS 15.2, macOS Monterey 12.1, Safari 15.2, iOS 15.2 and iPadOS 15.2, and watchOS 8.3. Systems running affected earlier versions should be upgraded to these fixed versions or later vendor-supported releases.
PUBLIC EXPLOITS

Exploits

No public exploits tracked yet. Mallory keeps watching.

VALID 0 / 0 TOTALView more in app

No public exploit code observed for this vulnerability.

EXPOSURE SURFACE

Affected products & vendors

Products and vendors Mallory has correlated with this vulnerability. Open in Mallory to drill down to specific CPE configurations and version ranges.

VendorProductType
AppleIpadosoperating_system
AppleIphone Osoperating_system
AppleMacosoperating_system
AppleSafariapplication
AppleTvosoperating_system
AppleWatchosoperating_system
DebianDebian Linuxoperating_system
Fedora ProjectFedoraoperating_system
WebkitgtkWebkitgtkapplication
WpewebkitWpe Webkitapplication

Vendor-confirmed product mapping. Mallory continuously reconciles this list against your asset inventory.

What this page doesn’t show

The version that knows your environment.

This page is what’s public. Mallory adds the parts that aren’t: which of your assets are affected, which adversaries are exploiting it right now, which detections to deploy, and what to do tonight.
Exposure mapping

Query your assets running an affected version, and investigate the blast radius.

Threat actor evidence18

Every observed campaign linking this CVE to a named adversary.

Associated malware23

Malware families riding this exploit, with evidence and IOCs.

Detection signatures1

YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.

Vendor-by-vendor mapping

Cross-references every affected SKU, including bundled OEM variants.

Social activity13

Community discussion across Reddit, Mastodon, and other social sources.