Vulnerability · CVE-2020-1631
Juniper Junos OS Path Traversal Vulnerability
Published May 4, 2020 · catalog updated Jun 16, 2026 · Juniper Junos OS
Patch now
CVE-2020-1631 is in the CISA known-exploited catalog, due Apr 15, 2022. Confirm Juniper Junos OS against the vendor advisory and apply that fix. The CVSS score does not change the priority.
- Severity
- Critical9.8
- Known exploitation
- CISA KEV and VulnCheck KEV
- EPSS
- 4.84%
- Remediation
- Remediation guidance
- Affected products
- cpe juniper/junos · vendor Juniper Junos OS
A vulnerability in the HTTP/HTTPS service used by J-Web, Web Authentication, Dynamic-VPN (DVPN), Firewall Authentication Pass-Through with Web-Redirect, and Zero Touch Provisioning (ZTP) allows an unauthenticated attacker to perform local file inclusion (LFI) or path traversal. Using this vulnerability, an attacker may be able to inject commands into the httpd.log, read files with 'world' readable permission file or obtain J-Web session tokens. In the case of command injection, as the HTTP service runs as user 'nobody', the impact of this command injection is limited. (CVSS score 5.3, vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N) In the case of reading files with 'world' readable permission, in Junos OS 19.3R1 and above, the unauthenticated attacker would be able to read the configuration file. (CVSS score 5.9, vector CVSS:3.1/ AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N) If J-Web is enabled, the attacker could gain the same level of access of anyone actively logged into J-Web. If an administrator is logged in, the attacker could gain administrator access to J-Web. (CVSS score 8.8, vector CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H) This issue only affects Juniper Networks Junos OS devices with HTTP/HTTPS services enabled. Junos OS devices with HTTP/HTTPS services disabled are not affected. If HTTP/HTTPS services are enabled, the following command will show the httpd processes: user@device> show system processes | match http 5260 - S 0:00.13 /usr/sbin/httpd-gk -N 5797 - I 0:00.10 /usr/sbin/httpd --config /jail/var/etc/httpd.conf To summarize: If HTTP/HTTPS services are disabled, there is no impact from this vulnerability. If HTTP/HTTPS services are enabled and J-Web is not in use, this vulnerability has a CVSS score of 5.9 (CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N). If J-Web is enabled, this vulnerability has a CVSS score of 8.8 (CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H). Juniper SIRT has received a single report of this vulnerability being exploited in the
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- cpe juniper/junos12.3
- vendor Juniper Junos OSversion unspecified
How to fix CVE-2020-1631
Recommended remediation
Apply updates per vendor instructions. CISA due date Apr 15, 2022.
Official advisories
What to do
Three questions, each answered from this record only. Confirm the vendor advisory before you patch.
Should you patch?
CVE-2020-1631 is in the CISA known-exploited catalog, due Apr 15, 2022. Confirm Juniper Junos OS against the vendor advisory and apply that fix. The CVSS score does not change the priority.
Which versions are affected?
Compare what you have installed with 12.3. Apply updates per vendor instructions.
What should an analyst verify?
CWE-22: Path Traversal; CWE-73. EPSS 4.84%. The CISA KEV listing is the exploitation evidence. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.
Code
The project this record applies to. Exploit listings stay in References.
No public source repository is identified for this product.
Timeline
Detection, updates, and resolution for this record.
May 4, 2020 · Catalog
Detected
A vulnerability in the HTTP/HTTPS service used by J-Web, Web Authentication, Dynamic-VPN (DVPN), Firewall Authentication Pass-Through with Web-Redirect, and Zero Touch Provisioning (ZTP) allows an unauthenticated attacker to perform local file inclusion (LFI) or path traversal. Using this vulnerability, an attacker may be able to inject commands into the httpd.log, read files with 'world' readable
Mar 25, 2022 · CISA KEV
Known exploited
Apply updates per vendor instructions.
Apr 15, 2022 · CISA KEV
Remediation due
Apply updates per vendor instructions.
Jun 16, 2026 · Catalog
Updated
A vulnerability in the HTTP/HTTPS service used by J-Web, Web Authentication, Dynamic-VPN (DVPN), Firewall Authentication Pass-Through with Web-Redirect, and Zero Touch Provisioning (ZTP) allows an unauthenticated attacker to perform local file inclusion (LFI) or path traversal. Using this vulnerability, an attacker may be able to inject commands into the httpd.log, read files with 'world' readable
Sources
- CISA KEVConfirmed exploitationCVE-2020-1631
A path traversal vulnerability in the HTTP/HTTPS service used by J-Web, Web Authentication, Dynamic-VPN (DVPN), Firewall Authentication Pass-Through with Web-Redirect, and Zero Touch Provisioning (ZTP) allows an unauthenticated attacker to perform remote code execution.
cisa.gov - CVE.orgVulnerability recordCVE-2020-1631
Official CVE identifier
cve.org - FIRST EPSSExploitation probabilityCVE-2020-1631
30-day exploitation probability 4.8%
first.org - NIST NVDVulnerability recordCVE-2020-1631
A vulnerability in the HTTP/HTTPS service used by J-Web, Web Authentication, Dynamic-VPN (DVPN), Firewall Authentication Pass-Through with Web-Redirect, and Zero Touch Provisioning (ZTP) allows an unauthenticated attacker to perform local file inclusion (LFI) or path traversal. U
nvd.nist.gov - VulnCheck KEVConfirmed exploitationCVE-2020-1631
A path traversal vulnerability in the HTTP/HTTPS service used by J-Web, Web Authentication, Dynamic-VPN (DVPN), Firewall Authentication Pass-Through with Web-Redirect, and Zero Touch Provisioning (ZTP) allows an unauthenticated attacker to perform remote code execution.
vulncheck.com
References
Freshness
Last verified in this catalog Oct 17, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.