How severe is CVE-2024-21620?

CVE-2024-21620 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2024-21620 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (56th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2024-21620?

CVE-2024-21620 primarily affects Juniper Junos. In total, 89 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2024-21620?

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.

Does CVE-2024-21620 have an EU (EUVD) identifier?

Yes. CVE-2024-21620 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2024-19268.

When was CVE-2024-21620 published?

CVE-2024-21620 was published on 2024-01-25 and last updated on 2026-06-17.

CVE-2024-21620

CVE-2024-21620 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-79.

Key facts

Severity: High (CVSS 3.x base score 8.8)
EPSS exploit prediction: 1% (56th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2024-19268
Weakness: CWE-79
Affected product: Juniper Junos
Published: 2024-01-25
Last modified: 2026-06-17

Description

An Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in J-Web of Juniper Networks Junos OS on SRX Series and EX Series allows an attacker to construct a URL that when visited by another user enables the attacker to execute commands with the target's permissions, including an administrator. A specific invocation of the emit_debug_note method in webauth_operation.php will echo back the data it receives. This issue affects Juniper Networks Junos OS on SRX Series and EX Series: * All versions earlier than 20.4R3-S10; * 21.2 versions earlier than 21.2R3-S8; * 21.4 versions earlier than 21.4R3-S6; * 22.1 versions earlier than 22.1R3-S5; * 22.2 versions earlier than 22.2R3-S3; * 22.3 versions earlier than 22.3R3-S2; * 22.4 versions earlier than 22.4R3-S1; * 23.2 versions earlier than 23.2R2; * 23.4 versions earlier than 23.4R2.

Frequently asked questions

What is CVE-2024-21620?: An Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in J-Web of Juniper Networks Junos OS on SRX Series and EX Series allows an attacker to construct a URL that when visited by another user enables the attacker to execute commands with the target's permissions, including an administrator. A specific invocation of the emit_debug_note method in webauth_operation.php will echo back the data it receives. This issue affects Juniper Networks Junos OS on SRX Series and EX Series: * All versions earlier than 20.4R3-S10; * 21.2 versions earlier than 21.2R3-S8; * 21.4 versions earlier than 21.4R3-S6; * 22.1 versions earlier than 22.1R3-S5; * 22.2 versions earlier than 22.2R3-S3; * 22.3 versions earlier than 22.3R3-S2; * 22.4 versions earlier than 22.4R3-S1; * 23.2 versions earlier than 23.2R2; * 23.4 versions earlier than 23.4R2.
How severe is CVE-2024-21620?: CVE-2024-21620 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2024-21620 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (56th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2024-21620?: CVE-2024-21620 primarily affects Juniper Junos. In total, 89 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2024-21620?: 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.
Does CVE-2024-21620 have an EU (EUVD) identifier?: Yes. CVE-2024-21620 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2024-19268.
When was CVE-2024-21620 published?: CVE-2024-21620 was published on 2024-01-25 and last updated on 2026-06-17.

References

https://supportportal.juniper.net/JSA76390

Affected products (89)

cpe:2.3:o:juniper:junos:*:*:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:20.4:-:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:20.4:r1:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:20.4:r1-s1:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:20.4:r2:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:20.4:r2-s1:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:20.4:r2-s2:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:20.4:r3:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:20.4:r3-s1:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:20.4:r3-s2:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:20.4:r3-s3:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:20.4:r3-s4:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:20.4:r3-s5:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:20.4:r3-s6:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:20.4:r3-s7:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:20.4:r3-s8:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:20.4:r3-s9:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:21.2:-:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:21.2:r1:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:21.2:r1-s1:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:21.2:r1-s2:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:21.2:r2:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:21.2:r2-s1:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:21.2:r2-s2:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:21.2:r3:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:21.2:r3-s1:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:21.2:r3-s2:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:21.2:r3-s3:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:21.2:r3-s4:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:21.2:r3-s5:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:21.2:r3-s6:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:21.2:r3-s7:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:21.4:-:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:21.4:r1:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:21.4:r1-s1:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:21.4:r1-s2:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:21.4:r2:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:21.4:r2-s1:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:21.4:r2-s2:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:21.4:r3:*:*:*:*:*:*

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