CVE-2021-0254

Vulnerability Summary

A buffer size validation vulnerability in the overlayd service of Juniper Networks Junos OS may allow an unauthenticated remote malicious user to send specially crafted packets to the device, triggering a partial Denial of Service (DoS) condition, or leading to remote code execution (RCE). Continued receipt and processing of these packets will sustain the partial DoS. The overlayd daemon handles Overlay OAM packets, such as ping and traceroute, sent to the overlay. The service runs as root by default and listens for UDP connections on port 4789. This issue results from improper buffer size validation, which can lead to a buffer overflow. Unauthenticated attackers can send specially crafted packets to trigger this vulnerability, resulting in possible remote code execution. overlayd runs by default in MX Series, ACX Series, and QFX Series platforms. The SRX Series does not support VXLAN and is therefore not vulnerable to this issue. Other platforms are also vulnerable if a Virtual Extensible LAN (VXLAN) overlay network is configured. This issue affects Juniper Networks Junos OS: 15.1 versions before 15.1R7-S9; 17.3 versions before 17.3R3-S11; 17.4 versions before 17.4R2-S13, 17.4R3-S4; 18.1 versions before 18.1R3-S12; 18.2 versions before 18.2R2-S8, 18.2R3-S7; 18.3 versions before 18.3R3-S4; 18.4 versions before 18.4R1-S8, 18.4R2-S7, 18.4R3-S7; 19.1 versions before 19.1R2-S2, 19.1R3-S4; 19.2 versions before 19.2R1-S6, 19.2R3-S2; 19.3 versions before 19.3R3-S1; 19.4 versions before 19.4R2-S4, 19.4R3-S1; 20.1 versions before 20.1R2-S1, 20.1R3; 20.2 versions before 20.2R2, 20.2R2-S1, 20.2R3; 20.3 versions before 20.3R1-S1.

Vulnerability Trend

References