CVE-2024-39552 in Junos OS
Summary
by MITRE • 07/11/2024
An Improper Handling of Exceptional Conditions vulnerability in the routing protocol daemon (RPD) of Juniper Networks Junos OS and Junos OS Evolved allows a network based, unauthenticated attacker to cause the RPD process to crash leading to a Denial of Service (DoS).
When a malformed BGP UPDATE packet is received over an established BGP session, RPD crashes and restarts.
Continuous receipt of the malformed BGP UPDATE messages will create a sustained Denial of Service (DoS) condition for impacted devices.
This issue affects eBGP and iBGP, in both IPv4 and IPv6 implementations. This issue requires a remote attacker to have at least one established BGP session.
This issue affects: Juniper Networks Junos OS: * All versions earlier than 20.4R3-S9; * 21.2 versions earlier than 21.2R3-S7; * 21.3 versions earlier than 21.3R3-S5; * 21.4 versions earlier than 21.4R3-S6; * 22.1 versions earlier than 22.1R3-S4; * 22.2 versions earlier than 22.2R3-S3; * 22.3 versions earlier than 22.3R3-S2; * 22.4 versions earlier than 22.4R3; * 23.2 versions earlier than 23.2R2.
Juniper Networks Junos OS Evolved: * All versions earlier than 21.2R3-S7; * 21.3-EVO versions earlier than 21.3R3-S5; * 21.4-EVO versions earlier than 21.4R3-S8; * 22.1-EVO versions earlier than 22.1R3-S4; * 22.2-EVO versions earlier than 22.2R3-S3; * 22.3-EVO versions earlier than 22.3R3-S2; * 22.4-EVO versions earlier than 22.4R3; * 23.2-EVO versions earlier than 23.2R2.
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Analysis
by VulDB Data Team • 07/31/2024
The vulnerability identified as CVE-2024-39552 represents a critical improper handling of exceptional conditions within the routing protocol daemon (RPD) of Juniper Networks Junos OS and Junos OS Evolved systems. This flaw manifests when the RPD process receives malformed BGP UPDATE packets over established BGP sessions, leading to immediate process crashes and subsequent restarts. The technical nature of this vulnerability aligns with CWE-703, which addresses improper handling of exceptional conditions, making it a classic example of how unhandled edge cases in network protocol implementations can lead to system instability. The vulnerability specifically targets the BGP routing protocol implementation, which forms the backbone of internet routing operations, making it particularly dangerous in network infrastructure contexts.
The operational impact of this vulnerability extends beyond simple service interruption to create sustained denial of service conditions when attackers continuously transmit malformed BGP UPDATE messages. This attack vector requires only a single established BGP session to be effective, making it accessible to remote attackers who may already have network connectivity to target devices. The vulnerability affects both external BGP (eBGP) and internal BGP (iBGP) implementations across both IPv4 and IPv6 protocols, demonstrating the comprehensive scope of the flaw. From an attacker perspective, this vulnerability maps directly to ATT&CK technique T1499.004, which involves network disruption through service availability attacks, and T1595.001 for initial access through network service exploitation.
The affected product lines span multiple Junos OS and Junos OS Evolved versions, with specific patch levels identified for each major release. This widespread impact across different version branches indicates that the underlying code flaw has persisted through multiple releases, suggesting a fundamental issue in the RPD's packet parsing or validation logic. The vulnerability affects not only traditional Junos OS deployments but also the newer Junos OS Evolved platform, highlighting that the issue is not limited to legacy implementations but extends to modern network infrastructure solutions. The requirement for established BGP sessions means that the attack cannot be launched blindly but requires either pre-existing network access or successful initial connection establishment, making this vulnerability somewhat more targeted than completely open attack vectors.
Network administrators should prioritize immediate patching of affected systems, as the vulnerability can be exploited remotely without authentication credentials. The sustained denial of service capability means that even brief attacks can cause significant network disruption, particularly in environments where BGP is critical for internet connectivity. Organizations should implement monitoring for unusual BGP session behavior and malformed packet traffic as early detection mechanisms. The vulnerability's classification as a DoS condition makes it particularly concerning for service providers and network operators who rely on stable routing protocols for maintaining network connectivity and service availability. Security teams should also consider implementing BGP traffic filtering and rate limiting as temporary mitigations while permanent patches are deployed, as this approach aligns with standard network security practices for handling malformed traffic in routing protocols.