Junos OS Evolved: shell-injection vulnerabilities in evo_tcpdump UI wrapper script
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 tcpdump 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 20.3R2-S1-EVO; 20.4 versions prior to 20.4R2-S2-EVO; 21.1 versions prior to 21.1R2-EVO; 21.2 versions prior to 21.2R1-S1-EVO, 21.2R2-EVO.
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Juniper | Junos OS Evolved | before 20.3R2-S1-EVO; 20.4 to before 20.4R2-S2-EVO; 21.1 to before 21.1R2-EVO; 21.2 to before 21.2R1-S1-EVO, 21.2R2-EVO | 20.3R2-S1-EVO, 20.4R2-S2-EVO, 21.1R2-EVO, 21.2R1-S1-EVO, 21.2R2-EVO | Patch available | CNA |
- Junos OS Evolved VendorJuniper Affected before 20.3R2-S1-EVO; 20.4 to before 20.4R2-S2-EVO; 21.1 to before 21.1R2-EVO; 21.2 to before 21.2R1-S1-EVO, 21.2R2-EVO Fixed in 20.3R2-S1-EVO, 20.4R2-S2-EVO, 21.1R2-EVO, 21.2R1-S1-EVO, 21.2R2-EVO Patch available CNA
CPE configurations NVD · 16
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:juniper:junos_os_evolved:*:*:*:*:*:*:*:* | up to 20.3 | Vulnerable | Juniper |
| cpe:2.3:o:juniper:junos_os_evolved:20.4:r1:*:*:*:*:*:* | 20.4 r1 | Vulnerable | Juniper |
| cpe:2.3:o:juniper:junos_os_evolved:20.4:r1-s1:*:*:*:*:*:* | 20.4 r1-s1 | Vulnerable | Juniper |
| cpe:2.3:o:juniper:junos_os_evolved:20.4:r1-s2:*:*:*:*:*:* | 20.4 r1-s2 | Vulnerable | Juniper |
| cpe:2.3:o:juniper:junos_os_evolved:20.4:r2:*:*:*:*:*:* | 20.4 r2 | Vulnerable | Juniper |
| cpe:2.3:o:juniper:junos_os_evolved:20.4:r2-s1:*:*:*:*:*:* | 20.4 r2-s1 | Vulnerable | Juniper |
| cpe:2.3:o:juniper:junos_os_evolved:20.4:r2-s2:*:*:*:*:*:* | 20.4 r2-s2 | Vulnerable | Juniper |
| cpe:2.3:o:juniper:junos_os_evolved:20.4:r2-s3:*:*:*:*:*:* | 20.4 r2-s3 | Vulnerable | Juniper |
| cpe:2.3:o:juniper:junos_os_evolved:20.4:r3:*:*:*:*:*:* | 20.4 r3 | Vulnerable | Juniper |
| cpe:2.3:o:juniper:junos_os_evolved:21.1:-:*:*:*:*:*:* | 21.1 | Vulnerable | Juniper |
- 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
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:juniper:junos_os_evolved:21.1:r1:*:*:*:*:*:* | 21.1 r1 | Vulnerable | Juniper |
| cpe:2.3:o:juniper:junos_os_evolved:21.1:r1-s1:*:*:*:*:*:* | 21.1 r1-s1 | Vulnerable | Juniper |
| cpe:2.3:o:juniper:junos_os_evolved:21.1:r2:*:*:*:*:*:* | 21.1 r2 | Vulnerable | Juniper |
| cpe:2.3:o:juniper:junos_os_evolved:21.2:r1:*:*:*:*:*:* | 21.2 r1 | Vulnerable | Juniper |
| cpe:2.3:o:juniper:junos_os_evolved:21.2:r1-s1:*:*:*:*:*:* | 21.2 r1-s1 | Vulnerable | Juniper |
| cpe:2.3:o:juniper:junos_os_evolved:21.2:r2:*:*:*:*:*:* | 21.2 r2 | Vulnerable | Juniper |
- 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 20.3R2-S1-EVO, 20.4R2-S2-EVO, 21.1R2-EVO, 21.2R1-S1-EVO, 21.2R2-EVO
Timeline
- 2026-10-02 Threatist record created from CVE-2021-31357
- 2026-10-03 Alias added: GHSA-6hf2-h4c4-m3pw
- 2026-10-27 EPSS moved to the 50th–90th percentile
References
Advisory 1
More Juniper Junos Os Evolved vulnerabilities
- 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
Sources
- CVE-2021-31357 · CVE Program
- CVE-2021-31357 · NVD
- FIRST EPSS
- GHSA-6hf2-h4c4-m3pw · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences