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CVE-2024-21591

Juniper Junos remote code execution

9.8 CRITICALEPSS 17.5%
  1. Published12 Jan 2024

Description

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.

CVSS 3.1 breakdown

Attack vectorNetwork
Attack complexityLow
Privileges requiredNone
User interactionNone
ScopeUnchanged
ConfidentialityHigh
IntegrityHigh
AvailabilityHigh
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected products

Juniper Junos< 20.4 · 20.4 · 21.2 · 21.3

Remediation

Fixed in
Juniper Junos≥ 20.4

Frequently asked

Is CVE-2024-21591 being actively exploited?

CVE-2024-21591 is not in the CISA KEV catalog. Its EPSS exploit probability is 17.5%.

How severe is CVE-2024-21591?

CVE-2024-21591 has a CVSS 3.1 base score of 9.8, rated critical. EPSS estimates a 17.5% probability of exploitation.

Which products are affected by CVE-2024-21591?

Affected products include Juniper Junos.

How do I fix CVE-2024-21591?

Upgrade affected software to a fixed version, for example Juniper Junos 20.4 or later, then confirm no affected versions remain in your inventory.

How Secuno handles this

Secuno correlates vulnerabilities like CVE-2024-21591 against the real software inventory on every managed device, every day. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.

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Data from the NVD, CISA KEV catalog and FIRST EPSS. CVSS 3.1 base score shown where available.