VYPR
Unrated severityNVD Advisory· Published Sep 23, 2021· Updated Nov 7, 2024

Cisco IOS XE SD-WAN Software Buffer Overflow Vulnerability

CVE-2021-34727

Description

A vulnerability in the vDaemon process in Cisco IOS XE SD-WAN Software could allow an unauthenticated, remote attacker to cause a buffer overflow on an affected device. This vulnerability is due to insufficient bounds checking when an affected device processes traffic. An attacker could exploit this vulnerability by sending crafted traffic to the device. A successful exploit could allow the attacker to cause a buffer overflow and possibly execute arbitrary commands with root-level privileges, or cause the device to reload, which could result in a denial of service condition.

AI Insight

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

A buffer overflow in the vDaemon process of Cisco IOS XE SD-WAN Software allows unauthenticated remote attackers to execute arbitrary commands with root privileges or cause a denial of service.

Vulnerability

A buffer overflow vulnerability exists in the vDaemon process of Cisco IOS XE SD-WAN Software. The issue stems from insufficient bounds checking when the device processes crafted traffic. Affected versions include Cisco IOS XE SD-WAN Software releases prior to the fixed versions specified in the Cisco advisory [1].

Exploitation

An unauthenticated, remote attacker can exploit this vulnerability by sending specially crafted traffic to the affected device. No authentication or user interaction is required. The attacker triggers the buffer overflow by sending malicious packets to the vDaemon process [1].

Impact

Successful exploitation can lead to a buffer overflow, potentially allowing the attacker to execute arbitrary commands with root-level privileges or cause the device to reload, resulting in a denial of service condition. This gives the attacker full control over the affected device [1].

Mitigation

Cisco has released free software updates to address this vulnerability. Customers should upgrade to the fixed versions indicated in the Cisco Security Advisory [1]. No workarounds are available. The advisory provides instructions for obtaining the updates through normal Cisco channels.

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

2

Patches

0

No patches discovered yet.

Vulnerability mechanics

AI mechanics synthesis has not run for this CVE yet.

References

1

News mentions

0

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