CVE-2021-1433

What it is

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 the device processes traffic. An attacker could exploit this vulnerability by sending crafted traffic to the device. The attacker must have a man-in-the-middle position between Cisco vManage and an associated device that is running an affected version of Cisco IOS XE SD-WAN Software. An exploit could allow the attacker to conduct a controllable buffer overflow attack (and possibly execute arbitrary commands as the root user) or cause a device reload, resulting in a denial of service (DoS) condition.

At a glance

Exploitability

Can be exploited over the network without logging in. High risk of data exposure, data tampering, service disruption.

Exploit odds

2.3% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2021-03-24 20:15 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-06-17 03:31 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 2.3% in the next 30 days (EPSS).
• Severity: 8.1 HIGH (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2021-03-24 20:15 UTC

Last modified

2026-06-17 03:31 UTC

Exploit probability

2.3% · EPSS, next 30 days

Weakness

CWE-119 · Buffer errors

Record status

Modified

Affected

• Cisco iOS Xe 3.15.1xbs
• Cisco iOS Xe 3.15.2xbs
• Cisco iOS Xe 16.12.1
• Cisco iOS Xe 16.12.1a
• Cisco iOS Xe 16.12.1c
• Cisco iOS Xe 16.12.1s
• Cisco iOS Xe 16.12.1t
• Cisco iOS Xe 16.12.1w

Attack profile CVSS 3.1 · 8.1

Attack vector

Network

Complexity

High

Privileges needed

None

User interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2021-1433.md and follow it. Check whether this project is affected by CVE-2021-1433. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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