CVE-2021-0254

Summary

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.

Affected Software

VendorProductVersion RangeStatus
Juniper NetworksJunos OS15.1 < 15.1R7-S9affected
Juniper NetworksJunos OS17.3 < 17.3R3-S11affected
Juniper NetworksJunos OS17.4 < 17.4R2-S13, 17.4R3-S4affected
Juniper NetworksJunos OS18.1 < 18.1R3-S12affected
Juniper NetworksJunos OS18.2 < 18.2R2-S8, 18.2R3-S7affected
Juniper NetworksJunos OS18.3 < 18.3R3-S4affected
Juniper NetworksJunos OS18.4 < 18.4R1-S8, 18.4R2-S7, 18.4R3-S7affected
Juniper NetworksJunos OS19.1 < 19.1R2-S2, 19.1R3-S4affected
Juniper NetworksJunos OS19.2 < 19.2R1-S6, 19.2R3-S2affected
Juniper NetworksJunos OS19.3 < 19.3R3-S1affected
Juniper NetworksJunos OS19.4 < 19.4R2-S4, 19.4R3-S1affected
Juniper NetworksJunos OS20.1 < 20.1R2-S1, 20.1R3affected
Juniper NetworksJunos OS20.2 < 20.2R2, 20.2R2-S1, 20.2R3affected
Juniper NetworksJunos OS20.3 < 20.3R1-S1affected

Weaknesses

  • CWE-131: CWE-131 Incorrect Calculation of Buffer Size
  • Denial of Service (DoS)

Workarounds

Two methods exist to mitigate this issue:

  1. Limit the exploitable attack surface of critical infrastructure networking equipment by using access lists or firewall filters to limit access to the device via UDP only from trusted, administrative networks or hosts.

  2. Disable Overlay OAM packet via the configuration command: 'set system processes overlay-ping-traceroute disable'

ADP Enrichment

CVE Program Container

Additional References

References