CVE-2024-20504 [Medium] | XSS in Asyncos

A vulnerability in the web-based management interface of Cisco AsyncOS Software for Cisco Secure Email and Web Manager, Secure Email Gateway, and Secure Web Appliance could allow an authenticated, remote attacker to conduct a stored cross-site scripting (XSS) attack against a user of the interface. This vulnerability is due to insufficient validation of user input. An attacker could exploit this vulnerability by persuading a user of an affected interface to click a crafted link. A successful exploit could allow the attacker to execute arbitrary script code in the context of the affected interface or access sensitive, browser-based information.

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2026-03-28	0.14%	0.19%	+0.05%
2	2025-12-17	0.16%	0.14%	-0.02%
3	2025-12-15	—	0.16%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2026-03-28

0.14%

0.19%

+0.05%

2025-12-17

0.16%

0.14%

-0.02%

2025-12-15

—

0.16%

—

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
5.4	3.1	MEDIUM	`CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/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:R) A real person has to do something—click, install, enable—otherwise it doesn’t land. Scope (S:C) Breaking this can reach past the original component and bite other resources—bigger blast radius. Confidentiality (C:L) Some sensitive info could get out, but not a total data dump. Integrity (I:L) Attackers could change some data, but it’s limited—not everything goes. Availability (A:N) Service keeps running; no real outage angle.	2.3	2.7	[email protected]

Base score

Version

Severity

Vector

Exploitability

Impact

Score source

5.4

3.1

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/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:R): A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:C): Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:L): Some sensitive info could get out, but not a total data dump.
Integrity (I:L): Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N): Service keeps running; no real outage angle.

2.3

2.7

[email protected]

Affected software / configurations for CVE-2024-20504

Vendor	Product	Version	Raw CPE
cisco	asyncos	14.0.0-698	cpe:2.3:o:cisco:asyncos:14.0.0-698:::::::*
cisco	asyncos	14.2.0-620	cpe:2.3:o:cisco:asyncos:14.2.0-620:::::::*
cisco	asyncos	14.2.1-020	cpe:2.3:o:cisco:asyncos:14.2.1-020:::::::*
cisco	asyncos	14.3.0-032	cpe:2.3:o:cisco:asyncos:14.3.0-032:::::::*
cisco	asyncos	15.0.0-104	cpe:2.3:o:cisco:asyncos:15.0.0-104:::::::*
cisco	asyncos	15.0.1-030	cpe:2.3:o:cisco:asyncos:15.0.1-030:::::::*
cisco	asyncos	15.5.0-048	cpe:2.3:o:cisco:asyncos:15.5.0-048:::::::*
cisco	asyncos	15.5.1-055	cpe:2.3:o:cisco:asyncos:15.5.1-055:::::::*
cisco	asyncos	14.0.0-404	cpe:2.3:o:cisco:asyncos:14.0.0-404:::::::*
cisco	asyncos	14.1.0-223	cpe:2.3:o:cisco:asyncos:14.1.0-223:::::::*
cisco	asyncos	14.1.0-227	cpe:2.3:o:cisco:asyncos:14.1.0-227:::::::*
cisco	asyncos	14.2.0-212	cpe:2.3:o:cisco:asyncos:14.2.0-212:::::::*
cisco	asyncos	14.2.0-224	cpe:2.3:o:cisco:asyncos:14.2.0-224:::::::*
cisco	asyncos	14.3.0-120	cpe:2.3:o:cisco:asyncos:14.3.0-120:::::::*
cisco	asyncos	15.0.0-334	cpe:2.3:o:cisco:asyncos:15.0.0-334:::::::*
cisco	asyncos	15.5.1-024	cpe:2.3:o:cisco:asyncos:15.5.1-024:::::::*
cisco	asyncos	15.5.1-029	cpe:2.3:o:cisco:asyncos:15.5.1-029:::::::*
cisco	asyncos	14.0.2-012	cpe:2.3:o:cisco:asyncos:14.0.2-012:::::::*
cisco	asyncos	14.0.3-014	cpe:2.3:o:cisco:asyncos:14.0.3-014:::::::*
cisco	asyncos	14.0.4-005	cpe:2.3:o:cisco:asyncos:14.0.4-005:::::::*
cisco	asyncos	14.0.5-007	cpe:2.3:o:cisco:asyncos:14.0.5-007:::::::*
cisco	asyncos	14.1.0-032	cpe:2.3:o:cisco:asyncos:14.1.0-032:::::::*
cisco	asyncos	14.1.0-041	cpe:2.3:o:cisco:asyncos:14.1.0-041:::::::*
cisco	asyncos	14.1.0-047	cpe:2.3:o:cisco:asyncos:14.1.0-047:::::::*
cisco	asyncos	14.5.0-498	cpe:2.3:o:cisco:asyncos:14.5.0-498:::::::*
cisco	asyncos	14.5.1-008	cpe:2.3:o:cisco:asyncos:14.5.1-008:::::::*
cisco	asyncos	14.5.1-016	cpe:2.3:o:cisco:asyncos:14.5.1-016:::::::*
cisco	asyncos	14.5.1-510	cpe:2.3:o:cisco:asyncos:14.5.1-510:::::::*
cisco	asyncos	14.5.1-607	cpe:2.3:o:cisco:asyncos:14.5.1-607:::::::*
cisco	asyncos	14.5.2-011	cpe:2.3:o:cisco:asyncos:14.5.2-011:::::::*
cisco	asyncos	14.5.3-033	cpe:2.3:o:cisco:asyncos:14.5.3-033:::::::*
cisco	asyncos	15.0.0-322	cpe:2.3:o:cisco:asyncos:15.0.0-322:::::::*
cisco	asyncos	15.0.0-355	cpe:2.3:o:cisco:asyncos:15.0.0-355:::::::*
cisco	asyncos	15.1.0-287	cpe:2.3:o:cisco:asyncos:15.1.0-287:::::::*
cisco	asyncos	15.2.0-116	cpe:2.3:o:cisco:asyncos:15.2.0-116:::::::*
cisco	asyncos	15.2.0-164	cpe:2.3:o:cisco:asyncos:15.2.0-164:::::::*

References for CVE-2024-20504

URL	Tags
https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-esa-wsa-sma-xss-zYm3f49n	Vendor Advisory

URL

CVE-2024-20504 | Cisco Secure Email and Web Manager, Secure Email Gateway, and Secure Web Appliance Stored Cross-Site Scripting Vulnerabilities

Exploit prediction scoring system (EPSS) score for CVE-2024-20504

Common vulnerability scoring system (CVSS) metrics for CVE-2024-20504

Weakness enumeration for CVE-2024-20504

Affected software / configurations for CVE-2024-20504

References for CVE-2024-20504