CVE-2026-40032

Description

UAC (Unix-like Artifacts Collector) before 3.3.0-rc1 contains a command injection vulnerability in the placeholder substitution and command execution pipeline where the _run_command() function passes constructed command strings directly to eval without proper sanitization. Attackers can inject shell metacharacters or command substitutions through attacker-controlled inputs including %line% values from foreach iterators and %user% / %user_home% values derived from system files to achieve arbitrary command execution with the privileges of the UAC process.

CVSS Details

CVSS Score

7.8

Severity

HIGH

CVSS Vector

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

Configurations (Affected Products)

No configuration data available.

UAC < 3.3.0-rc1

PoC / Exploit Code

⚠ For Security Research Only

The following code is for security research and authorized testing only.

python

# PoC Concept for CVE-2026-40032
# Create a malicious file to be scanned by UAC

import os

# Simulating the vulnerable function behavior
def vulnerable_run_command(template, line):
    # In the vulnerable version, this line effectively does:
    # command = template.replace("%line%", line)
    # eval(command)
    
    # Payload in 'line'
    malicious_payload = "; id #" 
    
    # The template command from UAC config
    cmd_template = "echo 'Processing file line: %line%'"
    
    # Construct the final command string
    final_cmd = cmd_template.replace("%line%", malicious_payload)
    
    print(f"[+] Executing: {final_cmd}")
    # The vulnerability allows this eval to execute the 'id' command
    try:
        # DO NOT RUN THIS IN PRODUCTION
        # eval(final_cmd) 
        pass 
    except Exception as e:
        print(e)

# Demonstration
vulnerable_run_command("echo %line%", "; touch /tmp/pwned #")

References

[1] CVE.org https://www.cve.org/CVERecord?id=CVE-2026-40032
[2] NVD NIST https://nvd.nist.gov/vuln/detail/CVE-2026-40032
[3] CVE Details https://www.cvedetails.com/cve/CVE-2026-40032/
[4] VulDB https://vuldb.com/cve/CVE-2026-40032
[5] https://github.com/tclahr/uac/commit/50ace60e172e38feb78347bdf579311c23eff078
[6] https://github.com/tclahr/uac/commit/cb95d7166cd47908e1189d9669e43f9a6d3d707f
[7] https://github.com/tclahr/uac/commit/d0fca5e36d8d6a33a4404f0f6fe92b0424544589
[8] https://github.com/tclahr/uac/issues/429
[9] https://github.com/tclahr/uac/pull/443
[10] https://mobasi.ai/sentinel
[11] https://www.vulncheck.com/advisories/uac-rc1-command-injection-via-placeholder-substitution

Raw JSON Data

JSON

{"cve": {"id": "CVE-2026-40032", "sourceIdentifier": "[email protected]", "published": "2026-04-08T22:16:23.827", "lastModified": "2026-04-13T15:02:47.353", "vulnStatus": "Awaiting Analysis", "cveTags": [], "descriptions": [{"lang": "en", "value": "UAC (Unix-like Artifacts Collector) before 3.3.0-rc1 contains a command injection vulnerability in the placeholder substitution and command execution pipeline where the _run_command() function passes constructed command strings directly to eval without proper sanitization. Attackers can inject shell metacharacters or command substitutions through attacker-controlled inputs including %line% values from foreach iterators and %user% / %user_home% values derived from system files to achieve arbitrary command execution with the privileges of the UAC process."}], "metrics": {"cvssMetricV40": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "4.0", "vectorString": "CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X", "baseScore": 8.5, "baseSeverity": "HIGH", "attackVector": "LOCAL", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "NONE", "userInteraction": "PASSIVE", "vulnConfidentialityImpact": "HIGH", "vulnIntegrityImpact": "HIGH", "vulnAvailabilityImpact": "HIGH", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "subAvailabilityImpact": "NONE", "exploitMaturity": "NOT_DEFINED", "confidentialityRequirement": "NOT_DEFINED", "integrityRequirement": "NOT_DEFINED", "availabilityRequirement": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "Safety": "NOT_DEFINED", "Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "valueDensity": "NOT_DEFINED", "vulnerabilityResponseEffort": "NOT_DEFINED", "providerUrgency": "NOT_DEFINED"}}], "cvssMetricV31": [{"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "REQUIRED", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 1.8, "impactScore": 5.9}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-78"}]}], "references": [{"url": "https://github.com/tclahr/uac/commit/50ace60e172e38feb78347bdf579311c23eff078", "source": "[email protected]"}, {"url": "https://github.com/tclahr/uac/commit/cb95d7166cd47908e1189d9669e43f9a6d3d707f", "source": "[email protected]"}, {"url": "https://github.com/tclahr/uac/commit/d0fca5e36d8d6a33a4404f0f6fe92b0424544589", "source": "[email protected]"}, {"url": "https://github.com/tclahr/uac/issues/429", "source": "[email protected]"}, {"url": "https://github.com/tclahr/uac/pull/443", "source": "[email protected]"}, {"url": "https://mobasi.ai/sentinel", "source": "[email protected]"}, {"url": "https://www.vulncheck.com/advisories/uac-rc1-command-injection-via-placeholder-substitution", "source": "[email protected]"}]}}