CVE-2024-21591: Junos OS: SRX Series and EX Series: Security Vulnerability in J-web allows a preAuth Remote Code Execution

Published Jan 12, 2024
·
Updated

An Out-of-bounds Write vulnerability in J-Web of Juniper Networks Junos OS on SRX Series and EX Series allows an unauthenticated, network-based attacker to cause a Denial of Service (DoS), or Remote Code Execution (RCE) and obtain root privileges on the device.

This issue is caused by use of an insecure function allowing an attacker to overwrite arbitrary memory.

This issue affects Juniper Networks Junos OS SRX Series and EX Series:

Junos OS versions earlier than 20.4R3-S9; Junos OS 21.2 versions earlier than 21.2R3-S7; Junos OS 21.3 versions earlier than 21.3R3-S5; Junos OS 21.4 versions earlier than 21.4R3-S5; Junos OS 22.1 versions earlier than 22.1R3-S4; Junos OS 22.2 versions earlier than 22.2R3-S3; Junos OS 22.3 versions earlier than 22.3R3-S2; Junos OS 22.4 versions earlier than 22.4R2-S2, 22.4R3.

Affected Software

92 affected components
Juniper Networks SRX Series firewall
Juniper Networks EX Series switch
Juniper Junos<20.4
Juniper Junos=20.4
Juniper Junos=20.4-r1
Juniper Junos=20.4-r1-s1
Juniper Junos=20.4-r2
Juniper Junos=20.4-r2-s1
Juniper Junos=20.4-r2-s2
Juniper Junos=20.4-r3
Juniper Junos=20.4-r3-s1
Juniper Junos=20.4-r3-s2
Juniper Junos=20.4-r3-s3
Juniper Junos=20.4-r3-s4
Juniper Junos=20.4-r3-s5
Juniper Junos=20.4-r3-s6
Juniper Junos=20.4-r3-s7
Juniper Junos=20.4-r3-s8
Juniper Junos=21.2
Juniper Junos=21.2-r1
Juniper Junos=21.2-r1-s1
Juniper Junos=21.2-r1-s2
Juniper Junos=21.2-r2
Juniper Junos=21.2-r2-s1
Juniper Junos=21.2-r2-s2
Juniper Junos=21.2-r3
Juniper Junos=21.2-r3-s1
Juniper Junos=21.2-r3-s2
Juniper Junos=21.2-r3-s3
Juniper Junos=21.2-r3-s4
Juniper Junos=21.2-r3-s5
Juniper Junos=21.2-r3-s6
Juniper Junos=21.3
Juniper Junos=21.3-r1
Juniper Junos=21.3-r1-s1
Juniper Junos=21.3-r1-s2
Juniper Junos=21.3-r2
Juniper Junos=21.3-r2-s1
Juniper Junos=21.3-r2-s2
Juniper Junos=21.3-r3
Juniper Junos=21.3-r3-s1
Juniper Junos=21.3-r3-s2
Juniper Junos=21.3-r3-s3
Juniper Junos=21.3-r3-s4
Juniper Junos=21.4
Juniper Junos=21.4-r1
Juniper Junos=21.4-r1-s1
Juniper Junos=21.4-r1-s2
Juniper Junos=21.4-r2
Juniper Junos=21.4-r2-s1
Juniper Junos=21.4-r2-s2
Juniper Junos=21.4-r3
Juniper Junos=21.4-r3-s1
Juniper Junos=21.4-r3-s2
Juniper Junos=21.4-r3-s3
Juniper Junos=21.4-r3-s4
Juniper Junos=22.1
Juniper Junos=22.1-r1
Juniper Junos=22.1-r1-s1
Juniper Junos=22.1-r1-s2
Juniper Junos=22.1-r2
Juniper Junos=22.1-r2-s1
Juniper Junos=22.1-r2-s2
Juniper Junos=22.1-r3
Juniper Junos=22.1-r3-s1
Juniper Junos=22.1-r3-s2
Juniper Junos=22.1-r3-s3
Juniper Junos=22.2
Juniper Junos=22.2-r1
Juniper Junos=22.2-r1-s1
Juniper Junos=22.2-r1-s2
Juniper Junos=22.2-r2
Juniper Junos=22.2-r2-s1
Juniper Junos=22.2-r2-s2
Juniper Junos=22.2-r3
Juniper Junos=22.2-r3-s1
Juniper Junos=22.2-r3-s2
Juniper Junos=22.3
Juniper Junos=22.3-r1
Juniper Junos=22.3-r1-s1
Juniper Junos=22.3-r1-s2
Juniper Junos=22.3-r2
Juniper Junos=22.3-r2-s1
Juniper Junos=22.3-r2-s2
Juniper Junos=22.3-r3
Juniper Junos=22.3-r3-s1
Juniper Junos=22.4
Juniper Junos=22.4-r1
Juniper Junos=22.4-r1-s1
Juniper Junos=22.4-r1-s2
Juniper Junos=22.4-r2
Juniper Junos=22.4-r2-s1

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade Junos OS (J-Web) to a version that resolves this vulnerability.

    Fixed in 20.4R3-S9
  2. Upgrade

    Upgrade Junos OS (J-Web) to a version that resolves this vulnerability.

    Fixed in 21.2R3-S7
  3. Upgrade

    Upgrade Junos OS (J-Web) to a version that resolves this vulnerability.

    Fixed in 21.3R3-S5
  4. Upgrade

    Upgrade Junos OS (J-Web) to a version that resolves this vulnerability.

    Fixed in 21.4R3-S5
  5. Upgrade

    Upgrade Junos OS (J-Web) to a version that resolves this vulnerability.

    Fixed in 22.1R3-S4
  6. Upgrade

    Upgrade Junos OS (J-Web) to a version that resolves this vulnerability.

    Fixed in 22.2R3-S3
  7. Upgrade

    Upgrade Junos OS (J-Web) to a version that resolves this vulnerability.

    Fixed in 22.3R3-S2
  8. Upgrade

    Upgrade Junos OS (J-Web) to a version that resolves this vulnerability.

    Fixed in 22.4R2-S2
  9. Upgrade

    Upgrade Junos OS (J-Web) to a version that resolves this vulnerability.

    Fixed in 22.4R3

Event History

Jan 12, 2024
CVE Published
via MITRE·12:52 AM
Data Sourced
via MITRE·12:52 AM
RemedyDescriptionSeverityWeakness
Data Sourced
via NVD·01:15 AM
DescriptionSeverityWeaknessAffected Software
News Published
05:36 PM
Jan 15, 2024
News Published
via The Register·07:34 PM
Jan 19, 2024
News Published
via The Register·07:38 PM

Peer vulnerabilities

Found alongside the following vulnerabilities.

Free Weekly Intel

Don't miss critical vulnerabilities

Join thousands of security professionals who receive our weekly digest of trending CVEs, zero-days, and exploited vulnerabilities.

No spam. Unsubscribe anytime.

Frequently Asked Questions

1

What is the severity of CVE-2024-21591?

CVE-2024-21591 is categorized as a critical vulnerability that can lead to Denial of Service (DoS) or Remote Code Execution (RCE) on affected devices.

2

How do I fix CVE-2024-21591?

To fix CVE-2024-21591, apply the latest security updates provided by Juniper Networks for the affected versions of Junos OS.

3

Which products are affected by CVE-2024-21591?

CVE-2024-21591 affects Juniper Networks SRX Series and EX Series devices running vulnerable versions of Junos OS.

4

Can CVE-2024-21591 be exploited remotely?

Yes, CVE-2024-21591 can be exploited by unauthenticated, network-based attackers, potentially giving them control over the device.

5

What versions of Junos OS are vulnerable to CVE-2024-21591?

CVE-2024-21591 impacts multiple versions of Junos OS including 20.4, 21.2, 21.3, 21.4, 22.1, 22.2, 22.3, and 22.4.

Contact

SecAlerts Pty Ltd.
132 Wickham Terrace
Fortitude Valley,
QLD 4006, Australia
info@secalerts.co
By using SecAlerts services, you agree to our services end-user license agreement. This website is safeguarded by reCAPTCHA and governed by the Google Privacy Policy and Terms of Service. All names, logos, and brands of products are owned by their respective owners, and any usage of these names, logos, and brands for identification purposes only does not imply endorsement. If you possess any content that requires removal, please get in touch with us.
© 2026 SecAlerts Pty Ltd.
ABN: 70 645 966 203, ACN: 645 966 203