CVE-2021-1516 [Medium] | Information Disclosure in Content Security Manageme…

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.

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2026-06-15	0.32%	1.16%	+0.84%
2	2025-11-21	0.21%	0.32%	+0.11%
3	2025-11-18	—	0.21%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2026-06-15

0.32%

1.16%

+0.84%

2025-11-21

0.21%

0.32%

+0.11%

2025-11-18

—

0.21%

—

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
4.3	3.1	MEDIUM	`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N` Click to expand Attack vector (AV:N) Could be attacked over the internet or any normal routed network—not just someone sitting at the machine. Attack complexity (AC:L) Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup. Privileges required (PR:L) A normal user session is enough; they don’t have to be admin. User interaction (UI:N) Nobody has to click “OK” or open a trap file; it can work without a victim helping. Scope (S:U) Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems. Confidentiality (C:L) Some sensitive info could get out, but not a total data dump. Integrity (I:N) Data isn’t meaningfully altered or forged. Availability (A:N) Service keeps running; no real outage angle.	2.8	1.4	[email protected]
6.5	3.1	MEDIUM	`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N` Click to expand Attack vector (AV:N) Could be attacked over the internet or any normal routed network—not just someone sitting at the machine. Attack complexity (AC:L) Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup. Privileges required (PR:L) A normal user session is enough; they don’t have to be admin. User interaction (UI:N) Nobody has to click “OK” or open a trap file; it can work without a victim helping. Scope (S:U) Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems. Confidentiality (C:H) Serious risk that confidential data gets exposed in a big way. Integrity (I:N) Data isn’t meaningfully altered or forged. Availability (A:N) Service keeps running; no real outage angle.	2.8	3.6	[email protected]
4.0	2.0	MEDIUM	`AV:N/AC:L/Au:S/C:P/I:N/A:N` Click to expand Access vector (AV:N) Can be exploited remotely over network reachability. Access complexity (AC:L) Exploitation conditions are straightforward and predictable. Authentication (AU:S) A single authentication is required. Confidentiality impact (C:P) Partial confidentiality impact. Integrity impact (I:N) No integrity impact. Availability impact (A:N) No availability impact.	8.0	2.9	[email protected]

Base score

Version

Severity

Vector

Exploitability

Impact

Score source

4.3

3.1

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N Click to expand

Attack vector (AV:N): Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L): Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L): A normal user session is enough; they don’t have to be admin.
User interaction (UI:N): Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U): Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:L): Some sensitive info could get out, but not a total data dump.
Integrity (I:N): Data isn’t meaningfully altered or forged.
Availability (A:N): Service keeps running; no real outage angle.

2.8

1.4

[email protected]

6.5

3.1

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N Click to expand

Attack vector (AV:N): Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L): Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L): A normal user session is enough; they don’t have to be admin.
User interaction (UI:N): Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U): Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H): Serious risk that confidential data gets exposed in a big way.
Integrity (I:N): Data isn’t meaningfully altered or forged.
Availability (A:N): Service keeps running; no real outage angle.

2.8

3.6

[email protected]

4.0

2.0

MEDIUM

AV:N/AC:L/Au:S/C:P/I:N/A:N Click to expand

Access vector (AV:N): Can be exploited remotely over network reachability.
Access complexity (AC:L): Exploitation conditions are straightforward and predictable.
Authentication (AU:S): A single authentication is required.
Confidentiality impact (C:P): Partial confidentiality impact.
Integrity impact (I:N): No integrity impact.
Availability impact (A:N): No availability impact.

8.0

2.9

[email protected]

Affected software / configurations for CVE-2021-1516

Vendor	Product	Version	Raw CPE
cisco	content_security_management_appliance	—	cpe:2.3:a:cisco:content_security_management_appliance:-:::::::*
cisco	email_security_appliance	—	cpe:2.3:a:cisco:email_security_appliance:-:::::::*
cisco	web_security_appliance	—	cpe:2.3:a:cisco:web_security_appliance:-:::::::*
cisco	ironport_web_security_appliance	13.6.2-023	cpe:2.3:a:cisco:ironport_web_security_appliance:13.6.2-023:::::::*
cisco	ironport_web_security_appliance	14.0.0-090	cpe:2.3:a:cisco:ironport_web_security_appliance:14.0.0-090:::::::*
cisco	ironport_web_security_appliance	14.0.0-133	cpe:2.3:a:cisco:ironport_web_security_appliance:14.0.0-133:::::::*
cisco	ironport_web_security_appliance	14.0.0-292	cpe:2.3:a:cisco:ironport_web_security_appliance:14.0.0-292:::::::*
cisco	ironport_web_security_appliance	14.0.0-300	cpe:2.3:a:cisco:ironport_web_security_appliance:14.0.0-300:::::::*

References for CVE-2021-1516

URL	Tags
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-esa-wsa-sma-info-gY2AEz2H	Vendor Advisory

URL

CVE-2021-1516 | Cisco Content Security Management Appliance, Email Security Appliance, and Web Security Appliance Information Disclosure Vulnerability

Exploit prediction scoring system (EPSS) score for CVE-2021-1516

Common vulnerability scoring system (CVSS) metrics for CVE-2021-1516

Weakness enumeration for CVE-2021-1516

Affected software / configurations for CVE-2021-1516

References for CVE-2021-1516