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IllumosOperating system

CVE-2021-43395

MEDIUM · 5.5 CVSS v3.1 Published 2022-12-26
Fix available
A fix is available. Upgrade to 2022-01-18 or later.
See remediation →
57/100
Remediation priority · Elevated
Public exploit Zero-click Patch available

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
An issue was discovered in illumos before f859e7171bb5db34321e45585839c6c3200ebb90, OmniOS Community Edition r151038, OpenIndiana Hipster 2021.04, and SmartOS 20210923. A local unprivileged user can cause a deadlock and kernel panic via crafted rename and rmdir calls on tmpfs filesystems. Oracle Solaris 10 and 11 is also affected.

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-667

Shared resources are accessed without correct locking, so concurrent operations interleave into inconsistent — and sometimes exploitable — states, or deadlock the service outright. These bugs are subtle and timing-dependent. The fix is correct, consistent locking or atomic operations around every shared resource.

General guidance for the improper locking 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
IllumosOperating system
Affected:< 2022-01-18
OmniosOperating system
Affected:= r151038
OpenindianaOperating system
Affected:= hipster_2021.04
SmartosOperating system
Affected:= 20210923
SolarisOperating system
Affected:= 10= 11

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
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

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.

dbcve · scoped
Upgrade available Upgrade to 2022-01-18 or later
Fixed in 2022-01-18
Vendor patch github.com →
Recommended fix High confidence

Any illumos-based distribution version released after 2022-01-18 that includes commit f859e7171bb5db34321e45585839c6c3200ebb90; for Omnios: r151039 or newer; for OpenIndiana: a Hipster release after 2021.04; for SmartOS: a platform release after 20210923; for Solaris: apply Oracle security patches

  1. 1. Identify the exact illumos-based distribution running (illumos, Omnios, OpenIndiana, SmartOS, or Oracle Solaris)
  2. 2. For illumos: Build and deploy a kernel from the illumos-gate repository at commit f859e7171bb5db34321e45585839c6c3200ebb90 or later
  3. 3. For Omnios r151038: Upgrade to Omnios r151039 or later stable release which includes the fix
  4. 4. For OpenIndiana Hipster 2021.04: Update to a newer Hipster release (post-2021.04) that incorporates the illumos fix
  5. 5. For SmartOS 20210923: Upgrade to a newer SmartOS platform release that includes the fix
  6. 6. For Oracle Solaris 10/11: Contact Oracle for the respective Solaris patch or ensure the system is on the latest Oracle Critical Patch Update
Caveat Ensure application compatibility with newer kernel; test in non-production environment first; some older kernel modules may require recompilation

Generated from the published advisory — verify against the referenced sources before acting.

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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-2021-43395 in production — separate from our analysis above.

No notes yet

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What this is

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What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
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