How severe is CVE-2021-31385?

CVE-2021-31385 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-31385 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (70th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-31385?

CVE-2021-31385 primarily affects Juniper Junos. In total, 211 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-31385?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2021-31385 published?

CVE-2021-31385 was published on 2021-10-19 and last updated on 2026-06-17.

CVE-2021-31385

CVE-2021-31385 is a high-severity vulnerability in Juniper Junos with a CVSS 3.x base score of 8.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-22.

Key facts

Severity: High (CVSS 3.x base score 8.8)
CVSS v2: 8.5
EPSS exploit prediction: 1% (70th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-22
Affected product: Juniper Junos
Published: 2021-10-19
Last modified: 2026-06-17

Description

An Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') vulnerability in J-Web of Juniper Networks Junos OS allows any low-privileged authenticated attacker to elevate their privileges to root. This issue affects: Juniper Networks Junos OS 12.3 versions prior to 12.3R12-S19; 15.1 versions prior to 15.1R7-S10; 18.3 versions prior to 18.3R3-S5; 18.4 versions prior to 18.4R3-S9; 19.1 versions prior to 19.1R3-S6; 19.2 versions prior to 19.2R1-S7, 19.2R3-S3; 19.3 versions prior to 19.3R3-S3; 19.4 versions prior to 19.4R3-S5; 20.1 versions prior to 20.1R2-S2, 20.1R3-S1; 20.2 versions prior to 20.2R3-S2; 20.3 versions prior to 20.3R3; 20.4 versions prior to 20.4R2-S1, 20.4R3; 21.1 versions prior to 21.1R1-S1, 21.1R2.

Frequently asked questions

What is CVE-2021-31385?: An Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') vulnerability in J-Web of Juniper Networks Junos OS allows any low-privileged authenticated attacker to elevate their privileges to root. This issue affects: Juniper Networks Junos OS 12.3 versions prior to 12.3R12-S19; 15.1 versions prior to 15.1R7-S10; 18.3 versions prior to 18.3R3-S5; 18.4 versions prior to 18.4R3-S9; 19.1 versions prior to 19.1R3-S6; 19.2 versions prior to 19.2R1-S7, 19.2R3-S3; 19.3 versions prior to 19.3R3-S3; 19.4 versions prior to 19.4R3-S5; 20.1 versions prior to 20.1R2-S2, 20.1R3-S1; 20.2 versions prior to 20.2R3-S2; 20.3 versions prior to 20.3R3; 20.4 versions prior to 20.4R2-S1, 20.4R3; 21.1 versions prior to 21.1R1-S1, 21.1R2.
How severe is CVE-2021-31385?: CVE-2021-31385 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-31385 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (70th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-31385?: CVE-2021-31385 primarily affects Juniper Junos. In total, 211 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-31385?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2021-31385 published?: CVE-2021-31385 was published on 2021-10-19 and last updated on 2026-06-17.

References

https://kb.juniper.net/JSA11253

Affected products (211)

cpe:2.3:o:juniper:junos:12.3:-:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:12.3:r1:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:12.3:r10:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:12.3:r10-s1:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:12.3:r10-s2:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:12.3:r11:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:12.3:r12:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:12.3:r12-s1:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:12.3:r12-s10:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:12.3:r12-s11:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:12.3:r12-s12:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:12.3:r12-s13:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:12.3:r12-s14:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:12.3:r12-s15:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:12.3:r12-s16:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:12.3:r12-s17:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:12.3:r12-s18:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:12.3:r12-s3:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:12.3:r12-s4:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:12.3:r12-s6:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:12.3:r12-s8:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:12.3:r2:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:12.3:r3:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:12.3:r4:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:12.3:r5:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:12.3:r6:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:12.3:r7:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:12.3:r8:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:12.3:r9:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:15.1:-:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:15.1:a1:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:15.1:f:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:15.1:f1:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:15.1:f2:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:15.1:f2-s1:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:15.1:f2-s2:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:15.1:f2-s3:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:15.1:f2-s4:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:15.1:f3:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:15.1:f4:*:*:*:*:*:*

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