CVE-2021-0254
Vulnérabilité critique dans Junos OS (Juniper Networks)
Description
A buffer size validation vulnerability in the overlayd service of Juniper Networks Junos OS may allow an unauthenticated remote attacker 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 prior to 15.1R7-S9; 17.3 versions prior to 17.3R3-S11; 17.4 versions prior to 17.4R2-S13, 17.4R3-S4; 18.1 versions prior to 18.1R3-S12; 18.2 versions prior to 18.2R2-S8, 18.2R3-S7; 18.3 versions prior to 18.3R3-S4; 18.4 versions prior to 18.4R1-S8, 18.4R2-S7, 18.4R3-S7; 19.1 versions prior to 19.1R2-S2, 19.1R3-S4; 19.2 versions prior to 19.2R1-S6, 19.2R3-S2; 19.3 versions prior to 19.3R3-S1; 19.4 versions prior to 19.4R2-S4, 19.4R3-S1; 20.1 versions prior to 20.1R2-S1, 20.1R3; 20.2 versions prior to 20.2R2, 20.2R2-S1, 20.2R3; 20.3 versions prior to 20.3R1-S1.
Gravité et risque d'exploitation
CVE-2021-0254 obtient un score CVSS de 9.8/10, soit une gravité critique. Selon le modèle EPSS, la probabilité qu'elle soit exploitée dans les 30 prochains jours est de 2.57 %, ce qui la place devant 84.9 % des CVE référencées.
Que faire ?
- Vérifiez si Junos OS (versions <15.1R7-S9, 19.2, <17.3R3-S11, <18.1R3-S12, 19.3, 20.1, <19.3R3-S1, 18.2, 20.3, <17.4R2-S13, 17.4R3-S4, 18.3, 19.1, 15.1, 18.1, 17.4, 18.4, 17.3, <20.1R2-S1, 20.1R3, <20.3R1-S1, 19.4, <19.2R1-S6, 19.2R3-S2, <19.1R2-S2, 19.1R3-S4, <20.2R2, 20.2R2-S1, 20.2R3, <18.2R2-S8, 18.2R3-S7, 20.2, <19.4R2-S4, 19.4R3-S1, <18.3R3-S4, <18.4R1-S8, 18.4R2-S7, 18.4R3-S7) est présent sur votre parc.
- Appliquez le correctif ou la version corrigée indiqués dans les références de l'éditeur.
- À défaut de correctif, limitez l'exposition (filtrage réseau, désactivation du composant).
- Automatisez la détection : les agents CVE Heimdall (gratuits, open source) corrèlent l'inventaire de vos serveurs avec la base CVE.