CVE-2026-33791

Description

An OS Command Injection vulnerability in the CLI processing of Juniper Networks Junos OS and Junos OS Evolved allows a local, high-privileged attacker executing specific, crafted CLI commands to inject arbitrary shell commands as root, leading to a complete compromise of the system. Certain 'set system' commands, when executed with crafted arguments, are not properly sanitized, allowing for arbitrary shell injection. These shell commands are executed as root, potentially allowing for complete control of the vulnerable system. This issue affects: Junos OS: * all versions before 22.4R3-S8, * from 23.2 before 23.2R2-S5, * from 23.4 before 23.4R2-S7, * from 24.2 before 24.2R2-S2, * from 24.4 before 24.4R2, * from 25.2 before 25.2R2; Junos OS Evolved: * all versions before 22.4R3-S8-EVO, * from 23.2 before 23.2R2-S5-EVO, * from 23.4 before 23.4R2-S7-EVO, * from 24.2 before 24.2R2-S2-EVO, * from 24.4 before 24.4R2-EVO, * from 25.2 before 25.2R1-S1-EVO, 25.2R2-EVO.

CVSS Details

CVSS Score

6.7

Severity

MEDIUM

CVSS Vector

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

Configurations (Affected Products)

cpe:2.3:o:juniper:junos:*:*:*:*:*:*:*:* - VULNERABLE

cpe:2.3:o:juniper:junos:22.4:-:*:*:*:*:*:* - VULNERABLE

cpe:2.3:o:juniper:junos:22.4:r1:*:*:*:*:*:* - VULNERABLE

cpe:2.3:o:juniper:junos:22.4:r1-s1:*:*:*:*:*:* - VULNERABLE

cpe:2.3:o:juniper:junos:22.4:r1-s2:*:*:*:*:*:* - VULNERABLE

cpe:2.3:o:juniper:junos_os_evolved:*:*:*:*:*:*:*:* - VULNERABLE

cpe:2.3:o:juniper:junos_os_evolved:22.4:-:*:*:*:*:*:* - VULNERABLE

cpe:2.3:o:juniper:junos_os_evolved:22.4:r1:*:*:*:*:*:* - VULNERABLE

cpe:2.3:o:juniper:junos_os_evolved:22.4:r1-s1:*:*:*:*:*:* - VULNERABLE

cpe:2.3:o:juniper:junos_os_evolved:22.4:r1-s2:*:*:*:*:*:* - VULNERABLE

Junos OS < 22.4R3-S8

Junos OS >= 23.2, < 23.2R2-S5

Junos OS >= 23.4, < 23.4R2-S7

Junos OS >= 24.2, < 24.2R2-S2

Junos OS >= 24.4, < 24.4R2

Junos OS >= 25.2, < 25.2R2

Junos OS Evolved < 22.4R3-S8-EVO

Junos OS Evolved >= 23.2, < 23.2R2-S5-EVO

Junos OS Evolved >= 23.4, < 23.4R2-S7-EVO

Junos OS Evolved >= 24.2, < 24.2R2-S2-EVO

Junos OS Evolved >= 24.4, < 24.4R2-EVO

Junos OS Evolved >= 25.2, < 25.2R1-S1-EVO, 25.2R2-EVO

PoC / Exploit Code

⚠ For Security Research Only

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

python

# Exploit Title: Junos OS CLI OS Command Injection PoC
# Description: Demonstrates injecting commands via crafted 'set system' arguments.
# Note: Requires high privileges (PR:H) and local access.

# Connect to the Junos CLI
cli

# Enter configuration mode
configure

# Attempt to inject a command using a crafted argument
# Replace 'vulnerable_parameter' with the specific parameter identified in the advisory.
# Example syntax: set system <vulnerable_parameter> "legitimate_value; <malicious_command>; #"

# Hypothetical injection to create a proof file:
set system <target_parameter> "normal_value; /bin/sh -c 'echo CVE-2026-33791 > /tmp/poc.txt'; #"

# Commit the changes to trigger the command execution
commit and-quit

# Verify execution (check /tmp/poc.txt)
file show /tmp/poc.txt

References

[1] CVE.org https://www.cve.org/CVERecord?id=CVE-2026-33791
[2] NVD NIST https://nvd.nist.gov/vuln/detail/CVE-2026-33791
[3] CVE Details https://www.cvedetails.com/cve/CVE-2026-33791/
[4] VulDB https://vuldb.com/cve/CVE-2026-33791
[5] https://kb.juniper.net/JSA107875
[6] https://supportportal.juniper.net/JSA107875

Raw JSON Data

JSON

{"cve": {"id": "CVE-2026-33791", "sourceIdentifier": "[email protected]", "published": "2026-04-09T22:16:29.047", "lastModified": "2026-04-22T15:16:14.387", "vulnStatus": "Modified", "cveTags": [], "descriptions": [{"lang": "en", "value": "An OS Command Injection vulnerability in the CLI processing of Juniper Networks Junos OS and Junos OS Evolved allows a local, high-privileged attacker executing specific, crafted CLI commands to inject arbitrary shell commands as root, leading to a complete compromise of the system.\n\nCertain 'set system' commands, when executed with crafted arguments, are not properly sanitized, allowing for arbitrary shell injection. These shell commands are executed as root, potentially allowing for complete control of the vulnerable system.\nThis issue affects:\n\nJunos OS: \n\n\n\n * all versions before 22.4R3-S8, \n * from 23.2 before 23.2R2-S5, \n * from 23.4 before 23.4R2-S7, \n * from 24.2 before 24.2R2-S2, \n * from 24.4 before 24.4R2, \n * from 25.2 before 25.2R2; \n\n\n\n\nJunos OS Evolved: \n\n\n\n * all versions before 22.4R3-S8-EVO, \n * from 23.2 before 23.2R2-S5-EVO, \n * from 23.4 before 23.4R2-S7-EVO, \n * from 24.2 before 24.2R2-S2-EVO, \n * from 24.4 before 24.4R2-EVO, \n * from 25.2 before 25.2R1-S1-EVO, 25.2R2-EVO."}], "metrics": {"cvssMetricV40": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "4.0", "vectorString": "CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:L/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:Y/R:A/V:C/RE:M/U:Amber", "baseScore": 8.4, "baseSeverity": "HIGH", "attackVector": "LOCAL", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "HIGH", "userInteraction": "NONE", "vulnConfidentialityImpact": "HIGH", "vulnIntegrityImpact": "HIGH", "vulnAvailabilityImpact": "HIGH", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "subAvailabilityImpact": "LOW", "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": "YES", "Recovery": "AUTOMATIC", "valueDensity": "CONCENTRATED", "vulnerabilityResponseEffort": "MODERATE", "providerUrgency": "AMBER"}}], "cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H", "baseScore": 6.7, "baseSeverity": "MEDIUM", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "HIGH", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 0.8, "impactScore": 5.9}]}, "weaknesses": [{"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-78"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:juniper:junos:*:*:*:*:*:*:*:*", "versionEndExcluding": "22.4", "matchCriteriaId": "57F66641-003B-49D6-A9B9-AB300CFE3C93"}, {"vulnerable": true, "criteria": "cpe:2.3:o:juniper:junos:22.4:-:*:*:*:*:*:*", "matchCriteriaId": "1379EF30-AF04-4F98-8328-52A631F24737"}, {"vulnerable": true, "criteria": "cpe:2.3:o:juniper:junos:22.4:r1:*:*:*:*:*:*", "matchCriteriaId": "28E42A41-7965-456B-B0AF-9D3229CE4D4C"}, {"vulnerable": true, "criteria": "cpe:2.3:o:juniper:junos:22.4:r1-s1:*:*:*:*:*:*", "matchCriteriaId": "CB1A77D6-D3AD-481B-979C-8F778530B175"}, {"vulnerable": true, "criteria": "cpe:2.3:o:juniper:junos:22.4:r1-s2:*:*:*:*:*:*", "matchCriteriaId": "3A064B6B-A99B-4D8D-A62D-B00C7870BC30"}, {"vulnerable": true, "criteria": "cpe:2.3:o:juniper:junos:22.4:r2:*:*:*:*:*:*", "matchCriteriaId": "40813417-A938-4F74-A419-8C5188A35486"}, {"vulnerable": true, "criteria": "cpe:2.3:o:juniper:junos:22.4:r2-s1:*:*:*:*:*:*", "matchCriteriaId": "7FC1BA1A-DF0E-4B15-86BA-24C60E546732"}, {"vulnerable": true, "criteria": "cpe:2.3:o:juniper:junos:22.4:r2-s2:*:*:*:*:*:*", "matchCriteriaId": "EBB967BF-3495-476D-839A-9DBFCBE69F91"}, {"vulnerable": true, "criteria": "cpe:2.3:o:juniper:junos:22.4:r3:*:*:*:*:*:*", "matchCriteriaId": "7E5688D6-DCA4-4550-9CD1-A3D792252129"}, {"vulnerable": true, "criteria": "cpe:2.3:o:juniper:junos:22.4:r3-s1:*:*:*:*:*:*", "matchCriteriaId": "8494546C-00EA-49B6-B6FA-FDE42CA5B1FA"}, {"vulnerable": true, "criteria": "cpe ... (truncated)