No exploitation reportedFix available

CVE-2021-31381

Q: Is CVE-2021-31381 actively exploited?

Active exploitation of CVE-2021-31381 has not been confirmed. Its EPSS score was 1.2% on 2026-10-23, the estimated probability of exploitation in the next 30 days.

Q: What is the CVSS score for CVE-2021-31381?

CVE-2021-31381 has a CVSS v3 base score of 9.1 (CRITICAL severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H.

No exploitation reported by the sources we read.

Published2021-10-19
Fixed in4.13.0r3 · 4.12.0r5
WeaknessCWE-16 · CWE-200

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

A configuration weakness in the JBoss Application Server (AppSvr) component of Juniper Networks SRC Series allows a remote attacker to send a specially crafted query to cause the web server to delete files which may allow the attacker to disrupt the integrity and availability of the system.

Timeline

dates in UTC

2021-10-1919:15CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-10-23 21:37 UTC

Indicators tagged with this CVE, per day0 indicators over 7 days

Block these indicators

Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2021-31381?format=txt
CSV export: https://api.ismalicious.com/edl/cve/CVE-2021-31381?format=csv
TAXII collection of exploited CVEs
The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD

Juniper session and resource control

Branch	Affected	Fixed in	Source
4.13	≥ 4.13.0r1, < 4.13.0r3	4.13.0r3	NVD
4.12	< 4.12.0r5	4.12.0r5	NVD

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Fix

Update Juniper session and resource control to 4.13.0r3 · 4.12.0r5

Advisories and patches

kb.juniper.netPatch · Vendor Advisory

Detection

Nuclei template: none so far
Exploit-DB: no entry
Proof-of-concept repositories: none listed

Sources

CNACVSS 3.16.5read 2026-10-23
NVDCVSS 3.19.1read 2026-10-23
NVDCVSS 2.06.4read 2026-10-23
CNAweakness (CWE)CWE-16, CWE-200read 2026-10-23
FIRST EPSSEPSS score1.2 %2026-10-23

Technical details

CVSS v3 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H
Published: 2021-10-19
Last Modified: 2026-06-17
NVD status: Modified

Frequently asked questions

What is CVE-2021-31381?

Is CVE-2021-31381 actively exploited?

Active exploitation of CVE-2021-31381 has not been confirmed. Its EPSS score was 1.2% on 2026-10-23, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2021-31381?

CVE-2021-31381 has a CVSS v3 base score of 9.1 (CRITICAL severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H.

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