CVE-2021-44078

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.

Published: 2021-12-26 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-44078 is rated Moderate Risk (40.3/100): CVSS High severity, with low exploitation likelihood (EPSS 0.08%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2021-44078

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-04-15 0.23% 0.08% -0.16%
2 2025-11-21 0.07% 0.23% +0.16%
3 2025-11-18 — 0.07% —

Full EPSS history (11 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-44078

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.1 3.1 HIGH
CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.4 6.0 [email protected]
6.9 2.0 MEDIUM
AV:L/AC:M/Au:N/C:C/I:C/A:C Click to expand
Access vector (AV:L)
Requires local access to the target system.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:C)
Complete confidentiality impact.
Integrity impact (I:C)
Complete integrity impact.
Availability impact (A:C)
Complete availability impact.
 3.4 10.0 [email protected]

Weakness enumeration for CVE-2021-44078

Affected software / configurations for CVE-2021-44078

Vendor Product Version Raw CPE
unicorn-engine unicorn_engine <= 1.0.3 cpe:2.3:a:unicorn-engine:unicorn_engine:*:*:*:*:*:*:*:*
unicorn-engine unicorn_engine 2.0.0 cpe:2.3:a:unicorn-engine:unicorn_engine:2.0.0:rc1:*:*:*:*:*:*
unicorn-engine unicorn_engine 2.0.0 cpe:2.3:a:unicorn-engine:unicorn_engine:2.0.0:rc2:*:*:*:*:*:*
unicorn-engine unicorn_engine 2.0.0 cpe:2.3:a:unicorn-engine:unicorn_engine:2.0.0:rc3:*:*:*:*:*:*
unicorn-engine unicorn_engine 2.0.0 cpe:2.3:a:unicorn-engine:unicorn_engine:2.0.0:rc4:*:*:*:*:*:*

References for CVE-2021-44078

cvelogic Threat Intelligence