SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2013-5537

The web framework on Cisco Web Security Appliance (WSA), Email Security Appliance (ESA), and Content Security Management Appliance (SMA) devices does not properly manage the state of HTTP and HTTPS sessions, which allows remote attackers to cause a…

HIGH 7.8EPSS 1.33%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (1.33%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

The web framework on Cisco Web Security Appliance (WSA), Email Security Appliance (ESA), and Content Security Management Appliance (SMA) devices does not properly manage the state of HTTP and HTTPS sessions, which allows remote attackers to cause a denial of service (management GUI outage) via multiple TCP connections, aka Bug IDs CSCuj59411, CSCuf89818, and CSCuh05635.

CVSS 2.0
7.8 HIGHAV:N/AC:L/Au:N/C:N/I:N/A:C
EPSS
1.33% probability · 71th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-20
Affected
cisco/web security appliance · cisco/content security management appliance · cisco/email security appliance firmware
Source
psirt@cisco.com
EPSS trend
0%3%5%26 October 2026: 1.33%26 October 202626 October 2026

EPSS 1.3% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.