CVE-2020-1631
CriticalExploitedPublic exploitA 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.
Published May 4, 2020 · Updated Oct 24, 2025
Key Facts
Patch immediately- CVE-2020-1631 is a critical-severity vulnerability (CVSS 9.8 v3.1) affecting Junos (Juniper), Junos OS.
- It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since May 4, 2020. Public exploit code is available.
- EPSS estimates a 4.8% probability of exploitation in the next 30 days.
- Fixed versions are available, including Junos OS 12.3R12-S16, Junos OS 12.3X48-D101, 12.3X48-D105, Junos OS 14.1X53-D54.
- Brandefense priority: patch immediately, because it is listed as exploited in the wild.
CVSS v3.1
9.8
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS (30-day exploit likelihood)
4.8%
Higher than 91.9% of all scored CVEs
Exploited in the wild
Yes
4 catalog listings
Public exploit code
Available
Proof-of-concept or weaponized module
Get the full CVE-2020-1631 brief as a PDF
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Description
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 wild. Out of an abundance of caution, we are notifying customers so they can take appropriate actions. Indicators of Compromise: The /var/log/httpd.log may have indicators that commands have injected or files being accessed. The device administrator can look for these indicators by searching for the string patterns "=*;*&" or "*%3b*&" in /var/log/httpd.log, using the following command: user@device> show log httpd.log | match "=*;*&|=*%3b*&" If this command returns any output, it might be an indication of malicious attempts or simply scanning activities. Rotated logs should also be reviewed, using the following command: user@device> show log httpd.log.0.gz | match "=*;*&|=*%3b*&" user@device> show log httpd.log.1.gz | match "=*;*&|=*%3b*&" Note that a skilled attacker would likely remove these entries from the local log file, thus effectively eliminating any reliable signature that the device had been attacked. This issue affects Juniper Networks Junos OS 12.3 versions prior to 12.3R12-S16; 12.3X48 versions prior to 12.3X48-D101, 12.3X48-D105; 14.1X53 versions prior to 14.1X53-D54; 15.1 versions prior to 15.1R7-S7; 15.1X49 versions prior to 15.1X49-D211, 15.1X49-D220; 16.1 versions prior to 16.1R7-S8; 17.2 versions prior to 17.2R3-S4; 17.3 versions prior to 17.3R3-S8; 17.4 versions prior to 17.4R2-S11, 17.4R3-S2; 18.1 versions prior to 18.1R3-S10; 18.2 versions prior to 18.2R2-S7, 18.2R3-S4; 18.3 versions prior to 18.3R2-S4, 18.3R3-S2; 18.4 versions prior to 18.4R1-S7, 18.4R3-S2 ; 18.4 version 18.4R2 and later versions; 19.1 versions prior to 19.1R1-S5, 19.1R3-S1; 19.1 version 19.1R2 and later versions; 19.2 versions prior to 19.2R2; 19.3 versions prior to 19.3R2-S3, 19.3R3; 19.4 versions prior to 19.4R1-S2, 19.4R2; 20.1 versions prior to 20.1R1-S1, 20.1R2.
Known-Exploited Catalog Listings
| Catalog | Added | Remediation due | Ransomware use |
|---|---|---|---|
| CISA KEV | Mar 25, 2022 | Apr 15, 2022 | Not reported |
| Industry KEV feed | May 4, 2020 | Apr 15, 2022 | Not reported |
| CIRCL KEV | Mar 25, 2022 | Apr 15, 2022 | Not reported |
| ENISA EUVD | Mar 25, 2022 | n/a | Not reported |
Required action: Apply updates per vendor instructions.
Affected Products
278 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| JunosJuniper | 12.3, 12.3-r1, 12.3-r10, 12.3-r10-s1, 12.3-r10-s2, 12.3-r11, 12.3-r12, 12.3-r12-s1 | n/a |
| Junos OS | >= 12.3 | 12.3R12-S16 |
Patched Releases
Junos OS
12.3R12-S16, 12.3X48-D101, 12.3X48-D105, 14.1X53-D54, 15.1R7-S7, 15.1X49-D211, 15.1X49-D220, 16.1R7-S8, 17.2R3-S4, 17.3R3-S8, 17.4R2-S11, 17.4R3-S2, 18.1R3-S10, 18.2R2-S7, 18.2R3-S4, 18.3R2-S4, 18.3R3-S2, 18.4R1-S7, 18.4R3-S2, 19.1R1-S5, 19.1R3-S1, 19.2R2, 19.3R2-S3, 19.3R3, 19.4R1-S2, 19.4R2, 20.1R1-S1, 20.1R2
Timeline
Publicly disclosed
May 4, 2020
Added to Industry KEV feed
May 4, 2020
Added to CISA KEV
Mar 25, 2022
Added to CIRCL KEV
Mar 25, 2022
Added to ENISA EUVD
Mar 25, 2022
Last updated
Oct 24, 2025
Weakness Type
- CWE-22 Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
- CWE-73 External Control of File Name or Path
References
FAQ
Common Questions.
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.
Affected: Junos (Juniper) versions 12.3, 12.3-r1, 12.3-r10, 12.3-r10-s1, 12.3-r10-s2, 12.3-r11, 12.3-r12, 12.3-r12-s1; Junos OS versions >= 12.3. The full list is in the CVE brief.
It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since May 4, 2020.
Yes. It was added on Mar 25, 2022 with a federal remediation due date of Apr 15, 2022.
Public exploit code is available.
Fixed versions are available, including Junos OS 12.3R12-S16, Junos OS 12.3X48-D101, 12.3X48-D105, Junos OS 14.1X53-D54.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.
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