CVE-2024-21620
High PUBLISHEDJunos OS: SRX Series and EX Series: J-Web doesn't sufficiently sanitize input to prevent XSS
Not yet in CISA KEV
Recommended Action
Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.
At a Glance
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.
- CVE Published
- Jan 25, 2024
- Exploitation Reported
- Mar 07, 2026
- CVSS
- 8.8 High
- EPSS
- —
Affected Versions
| Vendor | Product | Version | Status |
|---|---|---|---|
| Juniper Networks |
Junos OS
|
0 to < 20.4R3-S10 |
Affected |
| Juniper Networks |
Junos OS
|
21.2 to < 21.2R3-S8 |
Affected |
| Juniper Networks |
Junos OS
|
21.4 to < 21.4R3-S6 |
Affected |
| Juniper Networks |
Junos OS
|
22.1 to < 22.1R3-S5 |
Affected |
| Juniper Networks |
Junos OS
|
22.2 to < 22.2R3-S3 |
Affected |
| Juniper Networks |
Junos OS
|
22.3 to < 22.3R3-S2 |
Affected |
| Juniper Networks |
Junos OS
|
22.4 to < 22.4R3-S1 |
Affected |
| Juniper Networks |
Junos OS
|
23.2 to < 23.2R2 |
Affected |
| Juniper Networks |
Junos OS
|
23.4 to < 23.4R2 |
Affected |
CVE References
- Vendor Advisory — supportportal.juniper.net supportportal.juniper.net · Vendor Advisory https://supportportal.juniper.net/JSA76390
Recommended Actions
- Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.
- Use the Pro API to automate enrichment, telemetry, and workflow delivery for VM, SOC, and CTI pipelines.
Known Exploited Vulnerability Sources
Catalogues that list this CVE as a known exploited vulnerability.
Per-source evidence links for KEV attestations are available through the KEVIntel Pro API.
Learn about Pro API access| Source | Added |
|---|---|
| The Shadowserver First | 2026-03-07 00:00 UTC |
No detection artifacts or sensor request patterns are available for this CVE yet.
Check back as sensor telemetry and scanner integrations are updated.
Virtual Patch
Compensating WAF rules to help reduce exposure to this CVE. Rule content and deployable vendor exports are available with KEVIntel Enterprise.
KEVIntel does not currently have a virtual patch for this CVE. When available, KEVIntel virtual patches ship as deployable ModSecurity, Cloudflare, and AWS WAF rules.
Enterprise feature. Virtual patch rule content and deployable vendor exports (ModSecurity, Cloudflare, AWS WAF) are available to KEVIntel Enterprise users.
CVSS Scores
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Exploitation Status
Exploited in the wild
Recorded 2026-03-07 00:00:00 UTC · The Shadowserver
Weaknesses (CWE)
-
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Timeline
Key exploitation, disclosure, scanner coverage, and KEV attestation events for this CVE.
-
00:00 UTC 5 months ago00:00 UTC · 5 months ago
Added to KEVIntel KEV Feed
High-confidence, third-party attested exploitation
-
22:50 UTC over 2 years ago22:50 UTC · over 2 years ago
CVE published
Vulnerability disclosed publicly
-
19:38 UTC over 2 years ago19:38 UTC · over 2 years ago
CVE ID reserved
Identifier reserved by the CNA
Automate This Intelligence with the Pro API
Confidence scoring, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.
Pro API Example
GET /api/v2/pro/kevs/CVE-2024-21620
{
"cve_id": "CVE-2024-21620",
"title": "Junos OS: SRX Series and EX Series: J-Web doesn\'t sufficiently sanitize input...",
"affected_vendor": "Juniper Networks",
"affected_product": "Junos OS",
"affected_versions": [
{ "vendor": "...", "product": "...", "status": "affected", "display_label": "..." }
],
"confidence": "High",
"cvss_score": 8.8,
"epss_score": null,
"exploit_status": {
"exploited_in_the_wild": true,
"active_exploitation_observed": false
},
"sensor_telemetry": { "...": "Pro API fields" },
"proof_of_concepts": [ "..." ],
"scanner_integrations": [ "..." ]
}