Unicorn EngineApplication

CVE-2021-44078

HIGH · 8.1 CVSS v3.1 Published 2021-12-26
Fix available
A fix is available. Upgrade to after 1.0.3 or later.
See remediation →
86/100
Remediation priority · High
No privileges 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 split_region in uc.c in Unicorn Engine before 2.0.0-rc5. It allows local attackers to escape the sandbox. An attacker must first obtain the ability to execute crafted code in the target sandbox in order to exploit this vulnerability. The specific flaw exists within the virtual memory manager. The issue results from the faulty comparison of GVA and GPA while calling uc_mem_map_ptr to free part of a claimed memory block. An attacker can leverage this vulnerability to escape the sandbox and execute arbitrary code on the host machine.

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

A detailed technical summary for this CVE is being prepared.

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
Unicorn EngineApplication
Affected:<= 1.0.3= 2.0.0

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
High
Privileges
None
User interaction
None
Scope
Changed
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:C/C:H/I:H/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 a release after 1.0.3
Vendor patch github.com →
Recommended fix High confidence

Unicorn Engine 2.0.0-rc5 or later (e.g., 2.0.1, latest stable 2.x)

  1. 1. Identify all projects and dependencies that use Unicorn Engine in your environment
  2. 2. Check current Unicorn Engine version in use (either 1.0.3 or 2.0.0 based on affected versions)
  3. 3. Update the Unicorn Engine dependency to version 2.0.0-rc5 or later (preferably latest stable 2.x release)
  4. 4. Rebuild and recompile any applications that link against Unicorn Engine
  5. 5. Verify the fix is applied by confirming the vulnerable code in uc.c has been replaced with proper GVA-to-GPA comparison logic
  6. 6. Test that emulated code executes correctly in the updated sandbox environment
Caveat Upgrading from 1.0.x to 2.x may introduce API changes; review the Unicorn Engine changelog for breaking changes between major versions

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

We can identify the exact fixed release, upgrade, and verify it in staging — typical engagement from $1,950. Get the upgrade done

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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-2021-44078 in production — separate from our analysis above.

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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
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  • Version or environment caveats, and links to real fixes
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