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TI-2021-11500 Aliases CVE-2021-31356GHSA-fr6c-hwr9-4gr5

Junos OS Evolved: Multiple shell-injection vulnerabilities in EVO UI wrapper scripts

Priority LOW 36CWE-77Published · Updated

Key facts

Attack vector
Local
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
Code execution
Confidentiality · integrity · availability
High · High · High
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-77.

Summary

A command injection vulnerability in command processing on Juniper Networks Junos OS Evolved allows an attacker with authenticated CLI access to be able to bypass configured access protections to execute arbitrary shell commands within the context of the current user. The vulnerability allows an attacker to bypass command authorization restrictions assigned to their specific user account and execute commands that are available to the privilege level for which the user is assigned. For example, a user that is in the super-user login class, but restricted to executing specific CLI commands could exploit the vulnerability to execute any other command available to an unrestricted admin user. This vulnerability does not increase the privilege level of the user, but rather bypasses any CLI command restrictions by allowing full access to the shell. This issue affects Juniper Networks Junos OS Evolved: All versions prior to 20.4R3-S1-EVO; All versions of 21.1-EVO and 21.2-EVO.

Why it matters now

EPSS 0.00869 59th percentileScored 2026-11-07
Fix Fixed Junos OS Evolved (Juniper Networks): 20.4R3-S1-EVO

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

VendorProductAffected versionsFixed inStatusSource
JuniperJunos OS Evolvedbefore 20.4R3-S1-EVO; 21.1R1-EVO and later; 21.2R1-EVO and later20.4R3-S1-EVOPatch availableCNA
  • Junos OS Evolved VendorJuniper Affected before 20.4R3-S1-EVO; 21.1R1-EVO and later; 21.2R1-EVO and later Fixed in 20.4R3-S1-EVO Patch available CNA

CPE configurations NVD · 16

CPEVersionsRoleVendor
cpe:2.3:o:juniper:junos_os_evolved:*:*:*:*:*:*:*:*up to 20.3VulnerableJuniper
cpe:2.3:o:juniper:junos_os_evolved:20.4:r1:*:*:*:*:*:*20.4 r1VulnerableJuniper
cpe:2.3:o:juniper:junos_os_evolved:20.4:r1-s1:*:*:*:*:*:*20.4 r1-s1VulnerableJuniper
cpe:2.3:o:juniper:junos_os_evolved:20.4:r1-s2:*:*:*:*:*:*20.4 r1-s2VulnerableJuniper
cpe:2.3:o:juniper:junos_os_evolved:20.4:r2:*:*:*:*:*:*20.4 r2VulnerableJuniper
cpe:2.3:o:juniper:junos_os_evolved:20.4:r2-s1:*:*:*:*:*:*20.4 r2-s1VulnerableJuniper
cpe:2.3:o:juniper:junos_os_evolved:20.4:r2-s2:*:*:*:*:*:*20.4 r2-s2VulnerableJuniper
cpe:2.3:o:juniper:junos_os_evolved:20.4:r2-s3:*:*:*:*:*:*20.4 r2-s3VulnerableJuniper
cpe:2.3:o:juniper:junos_os_evolved:20.4:r3:*:*:*:*:*:*20.4 r3VulnerableJuniper
cpe:2.3:o:juniper:junos_os_evolved:21.1:-:*:*:*:*:*:*21.1VulnerableJuniper
  • cpe:2.3:o:juniper:junos_os_evolved:*:*:*:*:*:*:*:* Versions up to 20.3 Vulnerable ·Juniper
  • cpe:2.3:o:juniper:junos_os_evolved:20.4:r1:*:*:*:*:*:* Versions 20.4 r1 Vulnerable ·Juniper
  • cpe:2.3:o:juniper:junos_os_evolved:20.4:r1-s1:*:*:*:*:*:* Versions 20.4 r1-s1 Vulnerable ·Juniper
  • cpe:2.3:o:juniper:junos_os_evolved:20.4:r1-s2:*:*:*:*:*:* Versions 20.4 r1-s2 Vulnerable ·Juniper
  • cpe:2.3:o:juniper:junos_os_evolved:20.4:r2:*:*:*:*:*:* Versions 20.4 r2 Vulnerable ·Juniper
  • cpe:2.3:o:juniper:junos_os_evolved:20.4:r2-s1:*:*:*:*:*:* Versions 20.4 r2-s1 Vulnerable ·Juniper
  • cpe:2.3:o:juniper:junos_os_evolved:20.4:r2-s2:*:*:*:*:*:* Versions 20.4 r2-s2 Vulnerable ·Juniper
  • cpe:2.3:o:juniper:junos_os_evolved:20.4:r2-s3:*:*:*:*:*:* Versions 20.4 r2-s3 Vulnerable ·Juniper
  • cpe:2.3:o:juniper:junos_os_evolved:20.4:r3:*:*:*:*:*:* Versions 20.4 r3 Vulnerable ·Juniper
  • cpe:2.3:o:juniper:junos_os_evolved:21.1:-:*:*:*:*:*:* Versions 21.1 Vulnerable ·Juniper
Show 6 more CPE
CPEVersionsRoleVendor
cpe:2.3:o:juniper:junos_os_evolved:21.1:r1:*:*:*:*:*:*21.1 r1VulnerableJuniper
cpe:2.3:o:juniper:junos_os_evolved:21.1:r1-s1:*:*:*:*:*:*21.1 r1-s1VulnerableJuniper
cpe:2.3:o:juniper:junos_os_evolved:21.1:r2:*:*:*:*:*:*21.1 r2VulnerableJuniper
cpe:2.3:o:juniper:junos_os_evolved:21.2:r1:*:*:*:*:*:*21.2 r1VulnerableJuniper
cpe:2.3:o:juniper:junos_os_evolved:21.2:r1-s1:*:*:*:*:*:*21.2 r1-s1VulnerableJuniper
cpe:2.3:o:juniper:junos_os_evolved:21.2:r2:*:*:*:*:*:*21.2 r2VulnerableJuniper
  • cpe:2.3:o:juniper:junos_os_evolved:21.1:r1:*:*:*:*:*:* Versions 21.1 r1 Vulnerable ·Juniper
  • cpe:2.3:o:juniper:junos_os_evolved:21.1:r1-s1:*:*:*:*:*:* Versions 21.1 r1-s1 Vulnerable ·Juniper
  • cpe:2.3:o:juniper:junos_os_evolved:21.1:r2:*:*:*:*:*:* Versions 21.1 r2 Vulnerable ·Juniper
  • cpe:2.3:o:juniper:junos_os_evolved:21.2:r1:*:*:*:*:*:* Versions 21.2 r1 Vulnerable ·Juniper
  • cpe:2.3:o:juniper:junos_os_evolved:21.2:r1-s1:*:*:*:*:*:* Versions 21.2 r1-s1 Vulnerable ·Juniper
  • cpe:2.3:o:juniper:junos_os_evolved:21.2:r2:*:*:*:*:*:* Versions 21.2 r2 Vulnerable ·Juniper

Remediation

  • Fix · CNA Junos OS Evolved (Juniper Networks) Fixed in 20.4R3-S1-EVO

Timeline

  1. 2026-10-02 Threatist record created from CVE-2021-31356
  2. 2026-10-03 Alias added: GHSA-fr6c-hwr9-4gr5

References

Advisory 1

  • TI-2026-17602 Junos OS Evolved: PTX Series: A vulnerability allows a unauthenticated, network-based attacker to execute code as root CVSS 4.0CRITICAL 9.3
  • TI-2026-17601 Junos OS and Junos OS Evolved: Configuration of a specific SSH option results in mgd crash CVSS 4.0MEDIUM 6.7
  • TI-2023-04136 Improper input validation in Juniper Junos OS CVSS 3.1HIGH 7.5
  • TI-2026-74215 Stack-based buffer overflow in Junos OS rpd triggered by BGP peers CVSS 4.0CRITICAL 9.3
  • TI-2026-74211 Authentication bypass in Juniper J-Web allows pre-auth CGI execution CVSS 4.0CRITICAL 9.3
  • TI-2021-00146 Junos OS and Junos OS Evolved: Upon receipt of a specific BGP FlowSpec message network traffic may be disrupted. CVSS 3.1CRITICAL 10.0
See all 249 →

Sources

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