CVE-2021-1516

What it is

A vulnerability in the web-based management interface of Cisco AsyncOS Software for Cisco Content Security Management Appliance (SMA), Cisco Email Security Appliance (ESA), and Cisco Web Security Appliance (WSA) could allow an authenticated, remote attacker to access sensitive information on an affected device. The vulnerability exists because confidential information is included in HTTP requests that are exchanged between the user and the device. An attacker could exploit this vulnerability by looking at the raw HTTP requests that are sent to the interface. A successful exploit could allow the attacker to obtain some of the passwords that are configured throughout the interface.

At a glance

Exploitability

Can be exploited over the network with a low-privilege account. Limited direct impact.

Exploit odds

1.0% chance of exploitation in the next 30 days (EPSS).

Fix

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

Timeline

1. 2021-05-06 13:15 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: 1.0% in the next 30 days (EPSS).
• Severity: 4.3 MEDIUM (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2021-05-06 13:15 UTC

Last modified

2026-06-17 03:31 UTC

Exploit probability

1.0% · EPSS, next 30 days

Weakness

CWE-540

Record status

Modified

Affected

• Cisco Content Security Management Appliance
• Cisco Email Security Appliance
• Cisco Web Security Appliance
• Cisco Ironport Web Security Appliance 13.6.2-023
• Cisco Ironport Web Security Appliance 14.0.0-090
• Cisco Ironport Web Security Appliance 14.0.0-133
• Cisco Ironport Web Security Appliance 14.0.0-292
• Cisco Ironport Web Security Appliance 14.0.0-300

Attack profile CVSS 3.1 · 4.3

Attack vector

Network

Complexity

Low

Privileges needed

Low

User interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

None

Availability

None

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-2021-1516.md and follow it. Check whether this project is affected by CVE-2021-1516. 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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