VYPR
Unrated severityNVD Advisory· Published Jan 20, 2021· Updated Nov 12, 2024

Cisco SD-WAN Denial of Service Vulnerabilities

CVE-2021-1279

Description

Multiple vulnerabilities in Cisco SD-WAN products could allow an unauthenticated, remote attacker to execute denial of service (DoS) attacks against an affected device. For more information about these vulnerabilities, see the Details section of this advisory.

AI Insight

LLM-synthesized narrative grounded in this CVE's description and references.

Multiple unauthenticated remote DoS vulnerabilities in Cisco SD-WAN products allow attackers to cause device reboots or denial of service via crafted packets.

Vulnerability

Multiple denial of service (DoS) vulnerabilities exist in Cisco SD-WAN products, including vEdge Routers, vBond Orchestrator, vManage Software, vSmart Controller, and vEdge Cloud Routers. The vulnerabilities stem from insufficient handling of malformed packets and improper bounds checking in IPSec tunnel management. Affected software releases are those prior to the fixed versions provided in Cisco's advisory [1].

Exploitation

An unauthenticated, remote attacker can exploit these vulnerabilities by sending specially crafted IPv4 or IPv6 packets to an affected device. No authentication or user interaction is required. The attacker does not need prior access to the network beyond being able to send packets to the target device.

Impact

Successful exploitation causes the affected device to reboot or otherwise become unavailable, resulting in a denial of service condition. This can disrupt network operations and impact availability of SD-WAN services.

Mitigation

Cisco has released software updates that address these vulnerabilities. There are no workarounds. Users should upgrade to the latest fixed software versions as indicated in the Cisco Security Advisory [1].

AI Insight generated on May 26, 2026. Synthesized from this CVE's description and the cited reference URLs; citations are validated against the source bundle.

Affected products

1

Patches

0

No patches discovered yet.

Vulnerability mechanics

AI mechanics synthesis has not run for this CVE yet.

References

1

News mentions

0

No linked articles in our index yet.