CVE-2023-44204: Junos OS and Junos OS Evolved: The rpd will crash upon receiving a malformed BGP UPDATE message

Recommended actionScheduled

Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.

Patch available

What, why and how

An Improper Validation of Syntactic Correctness of Input vulnerability in Routing Protocol Daemon (rpd) Juniper Networks Junos OS and Junos OS Evolved allows an unauthenticated, network based attacker to cause a Denial of Service (DoS). When a malformed BGP UPDATE packet is received over an established BGP session, the rpd crashes and restarts. This issue affects both eBGP and iBGP implementations. This issue affects: Juniper Networks Junos OS * 21.4 versions prior to 21.4R3-S4; * 22.1 versions prior to 22.1R3-S3; * 22.2 versions prior to 22.2R3-S2; * 22.3 versions prior to 22.3R2-S2, 22.3R3; * 22.4 versions prior to 22.4R2-S1, 22.4R3; * 23.2 versions prior to 23.2R1, 23.2R2; Juniper Networks Junos OS Evolved * 21.4 versions prior to 21.4R3-S5-EVO; * 22.1 versions prior to 22.1R3-S3-EVO; * 22.2 versions prior to 22.2R3-S3-EVO; * 22.3 versions prior to 22.3R2-S2-EVO; * 22.4 versions prior to 22.4R3-EVO; * 23.2 versions prior to 23.2R2-EVO;

What

Why

The product receives input that is expected to be well-formed - i.e., to comply with a certain syntax - but it does not validate or incorrectly validates that the input complies with the syntax.

How

An attacker operating through an adjacent network may attempt exploitation without authentication or user interaction. If successful, the issue may disrupt the affected service.

What

Why

The product receives input that is expected to be well-formed - i.e., to comply with a certain syntax - but it does not validate or incorrectly validates that the input complies with the syntax.

How

An attacker operating through an adjacent network may attempt exploitation without authentication or user interaction. If successful, the issue may disrupt the affected service.

Exploit reality and attack path

CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.

Observed exploitation

Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.

No confirmed evidence

No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.

Public PoC / exploit material

Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.

None recorded

No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.

Likely attack path: an adjacent network → Improper Validation of Syntactic Correctness of Input → disrupt the affected service
Attack surface: Adjacent
Privileges required: None: unauthenticated exploitation is possible
User interaction: None
Attack complexity: Low: no specialised conditions are recorded
Security boundary: Unchanged: impact remains within the vulnerable component's security authority
Weakness ? CWE means Common Weakness Enumeration: a standard category for the underlying weakness.: CWE-1286 ↗
CWE-1286: Improper Validation of Syntactic Correctness of Input. The product receives input that is expected to be well-formed - i.e., to comply with a certain syntax - but it does not validate or incorrectly validates that the input complies with the syntax.
CVSS vector ? CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Common Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.
AVAdjacentAttack vector: The attacker must be on an adjacent or logically close network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRNonePrivileges required: The attacker does not need an account or existing privileges.UINoneUser interaction: No action by another user is required.SUnchangedScope: The security impact remains within the vulnerable component's authority.CNoneConfidentiality impact: No direct loss is represented by this metric.INoneIntegrity impact: No direct loss is represented by this metric.AHighAvailability impact: A successful attack can cause a major loss.
Post-exploitation / living off the land: No specific living-off-the-land technique is confirmed in the structured sources. Monitor normal administration tools for activity inconsistent with the affected service's baseline.

UnauthenticatedDenial of serviceCWE-1286

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

ENISA EUVD · EUVD-2023-48563Official EUVD mapping

0 linked advisory records.

Official EUVD record ↗

BSI · German · WID-SEC-2023-2636Juniper Patchday Oktober 2023

Ein entfernter, anonymer, authentisierter oder lokaler Angreifer kann mehrere Schwachstellen in verschiedenen Juniper Produkten ausnutzen, um Sicherheitsmaßnahmen zu umgehen, vertrauliche Informationen offenzulegen, einen Denial-of-Service-Zustand auszulösen und seine Privilegien zu erweitern.

Official advisory ↗

Cyber Security Agency of Singapore · English · CSA-SB-20231018Security Bulletin 18 Oct 2023

The Cyber Security Agency of Singapore included this CVE in its official Security Bulletin 18 Oct 2023, published on 18 October 2023. Open the linked bulletin for the product, severity and reference information published in that issue.

Official advisory ↗

CERT-FR · French · CERTFR-2023-AVI-0836Multiples vulnérabilités dans les produits Juniper

rtal.juniper.net/s/article/2023-10-Security-Bulletin-Junos-OS-Evolved-Specific-TCP-packets-will-bypass-a-control-plane-firewall-filter-CVE-2023-44202 Bulletin de sécurité Juniper JSA73169 du 11 octobre 2023 https://supportportal.juniper.net/s/article/2023-10-Security-Bulletin-Junos-OS-QFX5000-series-EX2300-EX3400-EX4100-EX4400-and-EX4600-Packet-flooding-will-occur-when-IGMP-traffic-is-sent-to-an-isolated-VLAN-CVE-2023-44203 Bulletin de sécurité Juniper JSA73170 du 11 octobre 2023 https://supportportal.juniper.net/s/article/2023-10-Security-Bulletin-Junos-OS-and-Junos-OS-Evolved-The-rpd-will-crash-upon-receiving-a-malformed-BGP-UPDATE-message-CVE-2023-44204 Bulletin de sécurité Juniper JSA73171 du 11 octobre 2023 https://supportportal.juniper.net/s/article/2023-10-Security-Bulletin-Junos-OS-and-Junos-OS-Evolved-An-l2cpd-crash-will-occur-when-specific-LLDP-packets-are-received-CVE-2023-36839 Bulletin de sécurité Juniper JSA73172 du 11 octobre 2023 https://supportportal.juniper.net/s/article/2023-10-Security-Bulletin-Junos-OS-MX-Series-Receipt-of-malformed-TCP-traffic-will-cause-a-Denial-of-Service-CVE-2023-36841 Bulletin de sécurité Juniper JSA73174 du 11 octobre 2023 https://supportportal.juniper.net/s/article/2023-10-Security-Bulletin-Junos-OS-SRX-Series-The-PFE-will-crash-on-receiving-malform

Official advisory ↗

JVN iPedia · Japanese · JVNDB-2023-014905ジュニパーネットワークスの Junos OS および Junos OS Evolved における入力確認に関する脆弱性

ジュニパーネットワークスの Junos OS および Junos OS Evolved には、入力確認に関する脆弱性が存在します。

Official advisory ↗

Patch and workaround

Operational remediation based on structured source evidence.

Status ? Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.: Patch available
Affected: Junos OS: 21.4 < 21.4R3-S4, 22.1 < 22.1R3-S3, 22.2 < 22.2R3-S2, 22.3 < 22.3R2-S2, 22.3R3, 22.4 < 22.4R2-S1, 22.4R3, 23.2 < 23.2R1, 23.2R2
Junos OS Evolved: 21.4-EVO < 21.4R3-S5-EVO, 22.1-EVO < 22.1R3-S3-EVO, 22.2-EVO < 22.2R3-S3-EVO, 22.3-EVO < 22.3R2-S2-EVO, 22.4-EVO < 22.4R3-EVO, 23.2-EVO < 23.2R2-EVO
Fixed: The following software releases have been updated to resolve this specific issue:
Junos OS: 21.4R3-S4, 22.1R3-S3, 22.2R3-S2, 22.3R2-S2, 22.3R3, 22.4R2-S1, 22.4R3, 23.1R2, 23.2R1, 23.2R2, 23.3R1 and all subsequent releases.
Junos OS Evolved: 22.1R3-S3-EVO, 22.3R2-S2-EVO, 22.4R3-EVO, 23.1R2-EVO, 23.2R2-EVO, 23.3R1-EVO and all subsequent releases.
Action: Review the linked authoritative reference and apply the recorded fixed release appropriate to the affected product branch.
Workaround: No verified workaround is recorded. Limit untrusted access and use least privilege until authoritative guidance is available.

Evidence and provenance

Published 12 Oct 2023 · Last source change 17 Sept 2024, 16:09 UTC · CWE-1286 · Improper Validation of Syntactic Correctness of Input

CVE recordCVE.org · 5.1

CVSS sourceCNA

EPSS source

The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.

FIRST · tracked since 2026-08-14

European sourceENISA EUVD · EUVD-2023-48563

Product sourceCNA

Remediation sourceCVE/CNA references

CWE sourceCNA

NVD statusNVD enriched

Core structured fields are present and their contributing authorities are shown above.

Material change intelligence

What changed after publication

View recent updates ↗

No material field changes have been recorded since change tracking began. Routine source refreshes and cosmetic edits are intentionally excluded.

2023-10-12CVE published

ENISA EUVD · EUVD-2023-48563↗CVE authority or vendor reference↗Official CVE record (CNA and ADP data)↗NVD record↗

Technical terms and abbreviations used in this report

CVE: Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS: Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS: Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE: Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA: CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP: Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD: National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT: A computer security incident response team that publishes warnings or coordinates incident response.
PoC: Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF: Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL: Living off the land: abuse of legitimate tools or system functions during an attack.

Junos OS and Junos OS Evolved: The rpd will crash upon receiving a malformed BGP UPDATE message

Published severity in operational context

Evidence used

Compensating controls

Verification

National CERT insights
?
CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

ENISA European Vulnerability Database

EUVD-2023-48563

What, why and how

Exploit reality and attack path

Official authority intelligence

Patch and workaround

Evidence and provenance

What changed after publication