How severe is CVE-2013-5537?

CVE-2013-5537 has a CVSS 2.0 base score of 7.8, rated high severity.

Is CVE-2013-5537 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (68th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2013-5537?

CVE-2013-5537 primarily affects Cisco Web Security Appliance. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2013-5537?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2013-5537 published?

CVE-2013-5537 was published on 2013-10-24 and last updated on 2026-06-16.

CVE-2013-5537

CVE-2013-5537 is a high-severity vulnerability in Cisco Web Security Appliance with a CVSS 2.0 base score of 7.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-20.

Key facts

Severity: High (CVSS 2.0 base score 7.8)
EPSS exploit prediction: 1% (68th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-20
Affected product: Cisco Web Security Appliance
Published: 2013-10-24
Last modified: 2026-06-16

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.

Frequently asked questions

What is 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 denial of service (management GUI outage) via multiple TCP connections, aka Bug IDs CSCuj59411, CSCuf89818, and CSCuh05635.
How severe is CVE-2013-5537?: CVE-2013-5537 has a CVSS 2.0 base score of 7.8, rated high severity.
Is CVE-2013-5537 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (68th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2013-5537?: CVE-2013-5537 primarily affects Cisco Web Security Appliance. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2013-5537?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2013-5537 published?: CVE-2013-5537 was published on 2013-10-24 and last updated on 2026-06-16.

References

http://tools.cisco.com/security/center/content/CiscoSecurityNotice/CVE-2013-5537

Affected products (3)

cpe:2.3:h:cisco:web_security_appliance:-:*:*:*:*:*:*:*
cpe:2.3:h:cisco:content_security_management_appliance:-:*:*:*:*:*:*:*
cpe:2.3:o:cisco:email_security_appliance_firmware:-:*:*:*:*:*:*:*

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