CVE-2021-31384
Junos OS: SRX Series: Under a specific device configuration an attacker can access the devices J-Web management services from any interface, regardless of security settings protecting the service
- Published
- Updated
- Reserved
- Assigned by
- juniper
Description
Due to a Missing Authorization weakness and Insufficient Granularity of Access Control in a specific device configuration, a vulnerability exists in Juniper Networks Junos OS on SRX Series whereby an attacker who attempts to access J-Web administrative interfaces can successfully do so from any device interface regardless of the web-management configuration and filter rules which may otherwise protect access to J-Web. This issue affects: Juniper Networks Junos OS SRX Series 20.4 version 20.4R1 and later versions prior to 20.4R2-S1, 20.4R3; 21.1 versions prior to 21.1R1-S1, 21.1R2. This issue does not affect Juniper Networks Junos OS versions prior to 20.4R1.
Timeline
ID reserved
By juniper
- 6 months later
· 6 months later
Published
- 3 years later
· 3 years later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| juniperCNA (assigner) | 3.1 | High7.2 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N |
| NVDNVD · Modified | 3.1 | Critical10.0 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 1.2% · top 33% of all CVEs (7 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.2.
Weakness
- CWE-285: Improper Authorization (opens in a new tab)All about CWE-285 and its CVEs
- CWE-862: Missing Authorization (opens in a new tab)All about CWE-862 and its CVEs
- CWE-551: Incorrect Behavior Order: Authorization Before Parsing and Canonicalization (opens in a new tab)All about CWE-551 and its CVEs
- CWE-939: Improper Authorization in Handler for Custom URL Scheme (opens in a new tab)All about CWE-939 and its CVEs
- CWE-1220: Insufficient Granularity of Access Control (opens in a new tab)All about CWE-1220 and its CVEs
Affected products
- unaffected unspecified – < 20.4R1
- affected 20.4R1 – < 20.4*
- affected 21.1 – < 21.1R1-S1, 21.1R2
What to do
Solution: The following software releases have been updated to resolve this specific issue: 20.4R2-S1, 20.4R3, 21.1R1-S1, 21.1R2, 21.2R1, and all subsequent releases.
Workaround: There are no viable workarounds for this issue other than disabling J-Web.
Exploitation: Juniper SIRT is not aware of any malicious exploitation of this vulnerability.
References (1)
- https://kb.juniper.net/ (opens in a new tab)x_refsource_MISCx_transferred
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2021-31384)Record last updated .