Mac Os XOperating system · Apple

CVE-2009-1238

HIGH · 7.2 CVSS v2.0 Published 2009-04-02
Fix available
A fix is available. Upgrade to after 10.5.6 or later.
See remediation →
77/100
Remediation priority · High
Public exploit No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Race condition in the HFS vfs sysctl interface in XNU 1228.8.20 and earlier on Apple Mac OS X 10.5.6 and earlier allows local users to cause a denial of service (kernel memory corruption) by simultaneously executing the same HFS_SET_PKG_EXTENSIONS code path in multiple threads, which is problematic because of lack of mutex locking for an unspecified global variable.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis
How this class of weakness works · CWE-362

Two operations that should be atomic can interleave, so an attacker who wins a narrow timing window reaches an inconsistent, exploitable state. These bugs are subtle and easy to miss in review. Fixing them properly means correct locking or atomic operations around the shared resource.

General guidance for the race condition class — the official description and references above are authoritative for this specific CVE. Want a bespoke review and a reviewed fix? Ask our team →

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Mac Os XOperating system
Affected:<= 10.5.6= 10.0= 10.0.0= 10.0.1= 10.0.2= 10.0.3= 10.0.4= 10.1= 10.1.0= 10.1.1= 10.1.2= 10.1.3
Mac Os X ServerOperating system
Affected:<= 10.5.6= 10.0= 10.0.0= 10.0.1= 10.0.2= 10.0.3= 10.0.4= 10.1= 10.1.0= 10.1.1= 10.1.2= 10.1.3

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Local
Complexity
Low
Authentication
None
Confidentiality
Complete
Integrity
Complete
Availability
Complete

AV:L/AC:L/Au:N/C:C/I:C/A:C

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Upgrade available Upgrade to a release after 10.5.6
We can identify the exact fixed release, upgrade, and verify it in staging — typical engagement from $1,950. Get the upgrade done

Scan for this in your stack

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2009-1238 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
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