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NVD / CVE Program· CNA mitre

CVE-2021-44078: An issue was discovered in split_region in uc.c in Unicorn Engine before 2.0.0-rc5.

Noroxi assessment

Priority: Monitor (action score 32/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.54% (FIRST EPSS).
  • Someone with local access to the system can trigger it. No account or password is required. No user action is required. Special conditions such as timing or configuration are required.
  • Fixed version: unicorn (PyPI) 2.0.0rc1.

Low priority for now. Upgrade to unicorn (PyPI) 2.0.0rc1 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

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.

HighCVSS 8.1 · v3.1—No exploit Fix available
Published
Dec 26, 2021
Updated
Jun 17, 2026
EPSS
0.5% · 46th percentile

Report tools

JSON

Action score

32

Monitor

Low priority for now.

CVSS
32 / 40 · 8.1 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.5%

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

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When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
unicorn-engineunicorn engine

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • unicorn-engine unicorn engineup to 1.0.3 inclusive
  • unicorn-engine unicorn engine2.0.0

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
PyPIunicornbefore 2.0.0rc12.0.0rc1

Same product

unicorn-engine: all records

Other highest-scoring records for the same primary product.

  • CVE-2022-29694Unicorn Engine v2.0.0-rc7 and below was discovered to contain a NULL pointer dereference via qemu_ram_free.
    31Monitor
  • CVE-2022-29692Unicorn Engine v1.0.3 was discovered to contain a use-after-free vulnerability via the hook function.
    31Monitor
  • CVE-2022-29695Unicorn Engine v2.0.0-rc7 contains memory leaks caused by an incomplete unicorn engine initialization.
    30Monitor

Published before and after this one in the same product

  • ← EarlierCVE-2020-36431Jul 20, 2021 · Unicorn Engine 1.0.2 has an out-of-bounds write in helper_wfe_arm.
    22Monitor
  • ← EarlierCVE-2021-36979Jul 20, 2021 · Unicorn Engine 1.0.2 has an out-of-bounds write in tb_flush_armeb (called from cpu_arm_exec_armeb and tcg_cpu_exec_armeb).
    22Monitor
  • Later →CVE-2022-29693Jun 2, 2022 · Unicorn Engine v2.0.0-rc7 and below was discovered to contain a memory leak via the function uc_close at /my/unicorn/uc.c.
    30Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
PyPI:unicorn2.0.0rc1Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Someone with local access to the system can trigger it.
  • No account or password is required.
  • No user action is required.
  • Special conditions such as timing or configuration are required.

If successful

Confidentiality
high · data can be read
Integrity
high · data or configuration can be modified
Availability
high · the service can be disrupted

Impact can extend beyond the vulnerable component (scope changes).

Attack vector
Local
Attack complexity
High
Privileges required
None
User interaction
None
Scope
Changed
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

CWE-697 · Incorrect Comparison

CVSS vector

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

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (4 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records