CISA KEV Critical File handling

CVE-2020-1631 — Juniper Junos OS Path Traversal Vulnerability

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.

Published May 4, 2020 · Updated Oct 13, 2026 · Sources: CISA Known Exploited Vulnerabilities, NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP, GitHub Security Advisories · CNA: juniper

High

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

CISA KEV · Mar 25, 2022

How the score was calculated

Confirmed exploitation (CISA KEV)+35
EPSS 4.8% (30-day exploitation probability)+14
Technical severity (critical)+10

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation

Confirmed

CISA KEV, listed Mar 25, 2022

EPSS FIRST

4.84%

ahead of 92% of scored CVEs · Oct 15, 2026

Affects

Juniper Networks

Junos and 1 more

CVSS base

9.8

Critical · 4 source(s)

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Exploitation

Active

none · proof-of-concept · active

Automatable

can an attacker script the kill-chain steps

Technical impact

Total

partial · total control of the vulnerable component

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

Documented mitigation — kb.juniper.net (NIST National Vulnerability Database)

CISA required action CISA

Apply updates per vendor instructions.

US federal deadline: Apr 15, 2022 — passed 1645 day(s) ago

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

Identify exposed assets running the affected vendor/product/version combinations (Juniper Networks Junos, Juniper Networks Junos OS).
Treat as emergency remediation: the CVE is in CISA KEV (confirmed exploitation).
The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
Apply the documented mitigations until a definitive fix is available.
EPSS ahead of 92% of scored CVEs: prioritize it in the patch queue.
Search available logs for exploit probes matching the vulnerability class (file handling), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

Vendor	Product	Versions	Status	Source
Juniper Networks	Junos	version 19.2-r1-s3version 19.1version 19.1-r1version 19.1-r1-s1version 19.1-r1-s2version 19.1-r1-s3version 19.1-r1-s4version 19.2 and 269 more version 19.2-r1version 19.2-r1-s1version 19.2-r1-s2version 18.3-r1-s6version 19.3version 19.3-r1version 19.3-r1-s1version 19.3-r2version 19.3-r2-s1version 19.3-r2-s2version 19.4-r1version 19.4-r1-s1version 20.1-r1version 18.4-r2-s3version 18.3-r1-s5version 18.3-r2version 18.3-r2-s1version 18.3-r2-s2version 18.3-r2-s3version 18.3-r3version 18.3-r3-s1version 18.4version 18.4-r1version 18.4-r1-s2version 18.4-r1-s1version 18.4-r3version 18.4-r2-s2version 18.4-r2-s1version 18.4-r2version 18.4-r1-s6version 18.4-r1-s5version 18.4-r1-s4version 18.4-r1-s3version 12.3version 12.3-r1version 12.3-r10version 12.3-r10-s1version 12.3-r10-s2version 12.3-r11version 12.3-r12version 12.3-r12-s1version 12.3-r12-s11version 12.3-r12-s12version 12.3-r12-s13version 12.3-r12-s14version 12.3-r12-s15version 12.3-r12-s3version 12.3-r12-s4version 12.3-r12-s6version 12.3-r12-s8version 12.3x48version 12.3x48-d10version 12.3x48-d100version 12.3x48-d15version 12.3x48-d20version 12.3x48-d25version 12.3x48-d30version 12.3x48-d35version 12.3x48-d40version 12.3x48-d45version 12.3x48-d50version 12.3x48-d51version 12.3x48-d55version 12.3x48-d60version 12.3x48-d65version 12.3x48-d70version 12.3x48-d75version 12.3x48-d80version 12.3x48-d85version 12.3x48-d90version 12.3x48-d95version 14.1x53version 14.1x53-d10version 14.1x53-d15version 14.1x53-d16version 14.1x53-d25version 14.1x53-d26version 14.1x53-d27version 14.1x53-d30version 14.1x53-d35version 14.1x53-d40version 14.1x53-d42version 14.1x53-d43version 14.1x53-d44version 14.1x53-d45version 14.1x53-d46version 14.1x53-d47version 14.1x53-d48version 14.1x53-d49version 14.1x53-d50version 14.1x53-d51version 14.1x53-d52version 14.1x53-d53version 15.1version 15.1-a1version 15.1-fversion 15.1-f1version 15.1-f2version 15.1-f2-s1version 15.1-f2-s2version 15.1-f2-s3version 15.1-f2-s4version 15.1-f3version 15.1-f4version 15.1-f5version 15.1-f5-s7version 15.1-f6version 15.1-f6-s1version 15.1-f6-s12version 15.1-f6-s2version 15.1-f6-s3version 15.1-f6-s4version 15.1-f6-s7version 15.1-f7version 15.1-r1version 15.1-r2version 15.1-r3version 15.1-r4version 15.1-r4-s7version 15.1-r4-s8version 15.1-r4-s9version 15.1-r5version 15.1-r5-s1version 15.1-r5-s5version 15.1-r5-s6version 15.1-r6version 15.1-r6-s1version 15.1-r6-s2version 15.1-r6-s6version 15.1-r7version 15.1-r7-s1version 15.1-r7-s2version 15.1-r7-s3version 15.1-r7-s4version 15.1-r7-s5version 15.1x49version 15.1x49-d10version 15.1x49-d100version 15.1x49-d110version 15.1x49-d120version 15.1x49-d130version 15.1x49-d140version 15.1x49-d15version 15.1x49-d150version 15.1x49-d160version 15.1x49-d170version 15.1x49-d180version 15.1x49-d190version 15.1x49-d20version 15.1x49-d200version 15.1x49-d210version 15.1x49-d25version 15.1x49-d30version 15.1x49-d35version 15.1x49-d40version 15.1x49-d45version 15.1x49-d50version 15.1x49-d55version 15.1x49-d60version 15.1x49-d65version 15.1x49-d70version 15.1x49-d75version 15.1x49-d80version 15.1x49-d90version 16.1version 16.1-r1version 16.1-r2version 16.1-r3version 16.1-r3-s10version 16.1-r3-s11version 16.1-r4version 16.1-r4-s12version 16.1-r4-s2version 16.1-r4-s3version 16.1-r4-s4version 16.1-r4-s6version 16.1-r5version 16.1-r5-s4version 16.1-r6-s1version 16.1-r6-s6version 16.1-r7version 16.1-r7-s2version 16.1-r7-s3version 16.1-r7-s4version 16.1-r7-s5version 16.1-r7-s6version 16.1-r7-s7version 17.2version 17.2-r1version 17.2-r1-s1version 17.2-r1-s2version 17.2-r1-s3version 17.2-r1-s4version 17.2-r1-s5version 17.2-r1-s7version 17.2-r1-s8version 17.2-r2version 17.2-r2-s11version 17.2-r2-s6version 17.2-r2-s7version 17.2-r3-s1version 17.2-r3-s2version 17.2-r3-s3version 17.3version 17.3-r1-s1version 17.3-r2version 17.3-r2-s1version 17.3-r2-s2version 17.3-r2-s3version 17.3-r2-s4version 17.3-r3version 17.3-r3-s1version 17.3-r3-s2version 17.3-r3-s3version 17.3-r3-s4version 17.3-r3-s7version 17.4version 17.4-r1version 17.4-r1-s1version 17.4-r1-s2version 17.4-r1-s4version 17.4-r1-s5version 17.4-r1-s6version 17.4-r1-s7version 17.4-r2version 17.4-r2-s1version 17.4-r2-s10version 17.4-r2-s2version 17.4-r2-s3version 17.4-r2-s4version 17.4-r2-s5version 17.4-r2-s6version 17.4-r2-s7version 17.4-r2-s8version 17.4-r2-s9version 17.4-r3version 17.4-r3-s1version 18.1version 18.1-r2version 18.1-r2-s1version 18.1-r2-s2version 18.1-r2-s4version 18.1-r3version 18.1-r3-s1version 18.1-r3-s2version 18.1-r3-s3version 18.1-r3-s4version 18.1-r3-s6version 18.1-r3-s7version 18.1-r3-s8version 18.1-r3-s9version 18.2version 18.2-r1-s3version 18.2-r1-s5version 18.2-r2-s1version 18.2-r2-s2version 18.2-r2-s3version 18.2-r2-s4version 18.2-r2-s5version 18.2-r2-s6version 18.2-r3version 18.2-r3-s1version 18.2-r3-s2version 18.2-r3-s3version 18.3version 18.3-r1version 18.3-r1-s1version 18.3-r1-s2version 18.3-r1-s3	Vulnerable	NIST National Vulnerability Database
Juniper Networks	Junos OS	≥ 20.1 and < 20.1R1-S1, 20.1R2≥ 19.4 and < 19.4R1-S2, 19.4R2≥ 19.3 and < 19.3R2-S3, 19.3R3≥ 19.2 and < 19.2R2≥ 19.1 and < 19.1R1-S5, 19.1R3-S1≥ 18.4 and < 18.4R1-S7, 18.4R3-S2≥ 18.3 and < 18.3R2-S4, 18.3R3-S2≥ 18.2 and < 18.2R2-S7, 18.2R3-S4 and 10 more ≥ 18.1 and < 18.1R3-S10≥ 17.4 and < 17.4R2-S11, 17.4R3-S2≥ 17.3 and < 17.3R3-S8≥ 17.2 and < 17.2R3-S4≥ 16.1 and < 16.1R7-S8≥ 15.1X49 and < 15.1X49-D211, 15.1X49-D220≥ 15.1 and < 15.1R7-S7≥ 14.1X53 and < 14.1X53-D54≥ 12.3X48 and < 12.3X48-D101, 12.3X48-D105≥ 12.3 and < 12.3R12-S16	Vulnerable	CVE Program (cve.org) e CISA ADP

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector

Network

Attack complexity

Low

Privileges required

None

User interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

Score	Version	Severity	Expl.	Impact	Scored by
9.8	CVSS 3.1	Critical	3.9	5.9	nvd@nist.gov via NIST National Vulnerability Database
9.8	CVSS 3.1	Critical	—	—	GitHub, Inc. via GitHub Security Advisories
8.8	CVSS 3.1	High	2.8	5.9	sirt@juniper.net via NIST National Vulnerability Database
8.8	CVSS 3.1	High	—	—	juniper via CVE Program (cve.org) e CISA ADP
6.8	CVSS 2.0	Medium	8.6	6.4	nvd@nist.gov via NIST National Vulnerability Database

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H (score shown at the top: nvd@nist.gov)

Scoring entities (NIST, CNA, ADP) score independently; each score is shown with its origin. For prioritization we use 9.8 (NVD (NIST)) as a conservative provisional reference — not a definitive official score.

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-22 · Path Traversal

Other CVEs with this weakness →

CISA KEV details CISA

CISA lists a CVE once it has evidence of exploitation against real targets.

Listed

Mar 25, 2022

Federal deadline

Apr 15, 2022

passed 1645 day(s) ago

Ransomware use

Unknown

CISA records ransomware use only for campaigns it has confirmed, so “Unknown” means unrecorded, not ruled out. The deadline binds US federal agencies; for everyone else it is a reference date.

EPSS over time FIRST

Oct 13, 2026 → Oct 15, 2026 · 3 reading(s) · max 4.84%

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
Monitor file creation in web directories and paths with traversal sequences (../).
Hunt retroactively in logs from before Mar 25, 2022 (KEV listing): exploitation may have started earlier.

web/proxy/WAF logsnetwork IDS/IPSfile integrity (FIM)endpoint telemetry (EDR)

Timeline

What happened to this CVE, newest first.

2026
Affected products added · juniper networks/junos os
Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
SSVC assessment updated
Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
Record published
Oct 13, 2026
Fix documented
Oct 13, 2026 · NIST National Vulnerability Database
Affected products added · juniper/junos
Oct 13, 2026 · NIST National Vulnerability Database
CVSS changed · 9.8
Oct 13, 2026 · NIST National Vulnerability Database
Source status changed · → Analyzed
Oct 13, 2026 · NIST National Vulnerability Database
Added to CISA KEV (detected)
Oct 13, 2026 · CISA Known Exploited Vulnerabilities
Record created in this database
Oct 13, 2026 · CISA Known Exploited Vulnerabilities
2022
Added to CISA KEV catalog
Mar 24, 2022 · CISA
2020
CVE published
May 4, 2020 · juniper

Source activity

Repeated readings are counted rather than listed.

2× References added · Oct 13, 2026 – Oct 13, 2026
1× Official description updated · Oct 13, 2026 – Oct 13, 2026

References

4 on the record

kb.juniper.net/JSA11021
Mitigation, Vendor Advisory, x_refsource_CONFIRM, NIST National Vulnerability Database
www.cisa.gov/known-exploited-vulnerabilities-catalog
US Government Resource, NIST National Vulnerability Database
nvd.nist.gov/vuln/detail/CVE-2020-1631
GitHub Security Advisories
github.com/advisories/GHSA-g762-xhjq-x42p
GitHub Security Advisories

Elsewhere on this site

Juniper Networks
every CVE for this vendor

2022-03
what else CISA listed that month

File handling
same class

CWE-22
other pages naming this weakness

Related CVEs (same products)

High CVE-2026-102077 Junos OS: MX Series with SPC3: In a source NAT scenario malformed packets will lead to resource leaks and eventually traffic stops 1d
Critical CVE-2026-101982 Junos OS and Junos OS Evolved: A EVPN peer causes an rpd crash or root-level compromise when EVPN-VPWS is used 1d
Critical CVE-2026-101983 Junos OS and Junos OS Evolved: An attacker causes remote code execution when J-Web virtual-domain is configured 1d
Medium CVE-2026-101964 Junos OS and Junos OS Evolved: An attacker can cause an rpd crash via a crafted LDP message 1d
Medium CVE-2026-101975 Junos OS and Junos OS Evolved: Improper OSPF LSA validation causes an rpd crash when prefix-SID best-route installation is used 1d
Medium CVE-2026-101972 Junos OS and Junos OS Evolved: Malformed OSPF packets causes routing disruption when OSPF is enabled 1d

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2020-1631 is "Juniper Junos OS Path Traversal Vulnerability", rated Critical. It affects Junos (Juniper Networks); versions are in the scope table. It is in CISA KEV: there is evidence of real-world exploitation. CVSS 9.8 describes technical severity. EPSS 4.84% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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