What is the CVSS score of CVE-2021-31353?

CVE-2021-31353 has a CVSS 3.1 base score of 7.5 (High). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. EPSS exploitation probability: 1.1%.

Is there a public PoC exploit available for CVE-2021-31353?

Yes, a public proof-of-concept exploit is available for CVE-2021-31353. Prioritise patching immediately. EPSS: 1.1%.

Junos CVE-2021-31353

HIGH

Improper Handling of Exceptional Conditions (CWE-755)

2021-10-19 sirt@juniper.net

Denial Of Service Juniper Junos Junos Os Evolved

7.5

CVSS 3.1 · Vendor: juniper

Severity by source

Vendor (juniper) PRIMARY

7.5 HIGH

AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Primary rating from Vendor (juniper) · only source for this CVE.

CVSS VectorVendor: juniper

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

Lifecycle Timeline

CVE Published

Oct 19, 2021 - 19:15 cve.org

HIGH 7.5

DescriptionCVE.org

An Improper Handling of Exceptional Conditions vulnerability in Juniper Networks Junos OS and Junos OS Evolved allows an attacker to inject a specific BGP update, causing the routing protocol daemon (RPD) to crash and restart, leading to a Denial of Service (DoS). Continued receipt and processing of the BGP update will create a sustained Denial of Service (DoS) condition. This issue affects very specific versions of Juniper Networks Junos OS: 19.3R3-S2; 19.4R3-S3; 20.2 versions 20.2R2-S3 and later, prior to 20.2R3-S2; 20.3 versions 20.3R2 and later, prior to 20.3R3; 20.4 versions 20.4R2 and later, prior to 20.4R3; 21.1 versions prior to 21.1R2. Juniper Networks Junos OS 20.1 is not affected by this issue. This issue also affects Juniper Networks Junos OS Evolved: All versions prior to 20.4R2-S3-EVO, 20.4R3-EVO; 21.1-EVO versions prior to 21.1R2-EVO; 21.2-EVO versions prior to 21.2R2-EVO.

AnalysisAI

An Improper Handling of Exceptional Conditions vulnerability in Juniper Networks Junos OS and Junos OS Evolved allows an attacker to inject a specific BGP update, causing the routing protocol daemon. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.

Technical ContextAI

This vulnerability is classified under CWE-755. An Improper Handling of Exceptional Conditions vulnerability in Juniper Networks Junos OS and Junos OS Evolved allows an attacker to inject a specific BGP update, causing the routing protocol daemon (RPD) to crash and restart, leading to a Denial of Service (DoS). Continued receipt and processing of the BGP update will create a sustained Denial of Service (DoS) condition.3R3-S2; 19.4R3-S3; 20.2 versions 20.2R2-S3 and later, prior to 20.2R3-S2; 20.3 versions 20.3R2 and later, prior to 20.3R3; 20.4 versions 20.4R2 and later, prior to 20.4R3; 21.1 versions prior to 21.1R2. Juniper Networks Junos OS 20.1 is not affected by this issue. This issue also affects Juniper Networks Junos OS Evolved: All versions prior to 20.4R2-S3-EVO, 20.4R3-EVO; 21.1-EVO versions prior to 21.1R2-EVO; 21.2-EVO versions prior to 21.2R2-EVO. Affected products include: Juniper Junos, Juniper Junos Os Evolved. Version information: prior to 20.2.

RemediationAI

No vendor patch is available at time of analysis. Monitor vendor advisories for updates. Apply vendor patches when available. Implement network segmentation and monitoring as interim mitigations.