CVE-2020-1631: Juniper Junos OS Path Traversal Vulnerability
- Is it exploited?
Yes. CISA added it to the Known Exploited Vulnerabilities catalog on , 690 days after the CVE record was published.
- How likely is exploitation in the next 30 days?
- 4.9%
EPSS score, percentile 92 of all scored records
- How severe?
- 8.8 High
CVSS v3.1 base score, given by the CNA
- What should I do?
CISA deadline . Apply updates per vendor instructions.
The CVE record links no vendor advisory, patch or mitigation.
- Which versions are affected?
Affected
- from 12.3 to before 12.3R12-S16
- from 12.3X48 to before 12.3X48-D101, 12.3X48-D105
- from 14.1X53 to before 14.1X53-D54
- from 15.1 to before 15.1R7-S7
- from 15.1X49 to before 15.1X49-D211, 15.1X49-D220
- from 16.1 to before 16.1R7-S8
and 6 more in the table below
Source: CISA Known Exploited Vulnerabilities (KEV) catalog, 2026.10.28, as of ; FIRST Exploit Prediction Scoring System (EPSS), v2026.06.15, as of ; CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of . About the data.
What to do
Required action, set by CISA
Apply updates per vendor instructions.
CISA due date for this action: .
Solution (from the CVE record)
The following software releases have been updated to resolve this specific issue: 12.3R12-S16, 12.3X48-D101, 12.3X48-D105, 14.1X53-D54, 15.1X49-D211, 15.1X49-D220, 15.1R7-S7, 16.1R7-S8, 17.2R3-S4, 17.4R2-S11, 17.3R3-S8, 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 and all subsequent releases. Note: At the time of this publication, the following fixed releases are available for customer download: 12.3X48-D101, 15.1X49-D211, 18.2R3-S4, 18.4R3-S2, and 20.1R1-S1, the remaining fixed releases will be available in future time. 12.3X48-D101 & 15.1X49-D211 releases can be downloaded from the below URLs: 12.3X48-D101 : Branch SRX-Series Install Package (for SRX100H2, SRX110HE2, SRX210H2, SRX220H2, SRX240H2, SRX550, SRX650): junos-srxsme-12.3X48-D101-domestic.tgz https://webdownload.juniper.net/swdl/dl/secure/site/1/record/107438.html MD5 = b822376f7a385e74499b186cf28c122b SHA-1 = e6138e45bf9d29e962468e6e114e537142d4cc0d SHA-256 = b21a9ae9f5d0b0ec25180682193faba7bf54e836fda0eb78babd3df843f90e6a SRX 1000/3000-Series Install Package : junos-srx1k3k-12.3X48-D101-domestic.tgz https://webdownload.juniper.net/swdl/dl/secure/site/1/record/107436.html MD5 = b93229ea43f66b539f22ecc5a9be0f07 SHA-1 = 2c625e9bc155b9fcb4c9a1a371bba473363ee6f0 SHA-256 = 982434f9cde9492e1d80d14c43a7cdcc5261db15a11f65fa7c9881a0fc0cd3db SRX5000-Series Install Package: junos-srx5000-12.3X48-D101-domestic.tgz https://webdownload.juniper.net/swdl/dl/secure/site/1/record/107437.html MD5 = 7dc73801b7680fda42d453d6d3d6f10c SHA-1 = 05f1eda5ec112c7e2afeebea4d47c007e0a8bd60 SHA-256 = 88d40e4b6b949a5c656c2b5fffa3adb41fe4943fb3e5d9cfaa439e603889e839 15.1X49-D211: SRX300 & SRX500-Series Install Package: junos-srxsme-15.1X49-D211-domestic.tgz https://webdownload.juniper.net/swdl/dl/secure/site…
Workaround (from the CVE record)
There are no viable workarounds for this issue. It is highly recommended to disable HTTP/HTTPS service and DVPN: user@device# deactivate system services web-management user@device# deactivate security dynamic-vpn (if DVPN is enabled) user@device# commit or allowing HTTP service only on from trusted hosts or networks (refer to https://kb.juniper.net/KB21265 for details on how to limite HTTP service).
Advisories and patches
The CVE record links no vendor advisory, patch or mitigation.
Linked from CISA's catalog entry
Affected products and versions
As listed in the CVE record.
| Status | Versions |
|---|---|
| Affected | from 12.3 to before 12.3R12-S16 |
| Affected | from 12.3X48 to before 12.3X48-D101, 12.3X48-D105 |
| Affected | from 14.1X53 to before 14.1X53-D54 |
| Affected | from 15.1 to before 15.1R7-S7 |
| Affected | from 15.1X49 to before 15.1X49-D211, 15.1X49-D220 |
| Affected | from 16.1 to before 16.1R7-S8 |
| Affected | from 17.2 to before 17.2R3-S4 |
| Affected | from 17.3 to before 17.3R3-S8 |
| Affected | from 17.4 to before 17.4R2-S11, 17.4R3-S2 |
| Affected | from 18.1 to before 18.1R3-S10 |
| Affected | from 18.2 to before 18.2R2-S7, 18.2R3-S4 |
| Affected | from 18.3 to before 18.3R2-S4, 18.3R3-S2 |
And 8 more version entries in the CVE record.
Source: CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of . About the data.
About this vulnerability
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.
Summary: CISA's KEV catalog, as of .
- CISA added CVE-2020-1631 to its Known Exploited Vulnerabilities (KEV) catalog on 25 Mar 2022.
- CISA's ransomware flag for this entry is "Unknown": no evidence of ransomware use in the catalog, which is not proof of none.
- The due date CISA sets for the required action is 15 Apr 2022.
- The CVE record was published on 4 May 2020, 690 days before it was added to KEV.
- The CVE record carries a CVSS v3.1 base score of 8.8 (High), given by its CNA.
- FIRST's EPSS model puts the probability of exploitation in the next 30 days at 4.9% (percentile 92), as of 28 Oct 2026.
- CISA's SSVC assessment in the CVE record: exploitation active, automatable no, technical impact total.
Source: CISA Known Exploited Vulnerabilities (KEV) catalog, 2026.10.28, as of ; CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of ; FIRST Exploit Prediction Scoring System (EPSS), v2026.06.15, as of . About the data.
Description
Out of Cycle Security Advisory: Junos OS: Security vulnerability in J-Web and web based (HTTP/HTTPS) services
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.
Source: CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of . About the data.
Weakness
- CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
- CWE-73: External Control of File Name or Path
CWE and CAPEC are maintained by MITRE; the entries are those named in the CVE record and the KEV entry.
Timeline
| Date | Event |
|---|---|
| CVE record published | |
| Added to CISA KEV | |
| CISA due date for the required action | |
| CVE record last updated |
References
More exploited Juniper vulnerabilities
- CVE-2015-7755: Juniper ScreenOS Improper Authentication Vulnerability
- CVE-2025-21590: Juniper Junos OS Improper Isolation or Compartmentalization Vulnerability
- CVE-2023-36844: Juniper Junos OS EX Series PHP External Variable Modification Vulnerability
- CVE-2023-36845: Juniper Junos OS EX Series and SRX Series PHP External Variable Modification Vulnerability
- CVE-2023-36846: Juniper Junos OS SRX Series Missing Authentication for Critical Function Vulnerability
- CVE-2023-36847: Juniper Junos OS EX Series Missing Authentication for Critical Function Vulnerability