How severe is CVE-2015-6309?

CVE-2015-6309 has a CVSS 2.0 base score of 6.8, rated medium severity.

Is CVE-2015-6309 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (74th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2015-6309?

CVE-2015-6309 primarily affects Cisco Email Security Appliance. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2015-6309?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2015-6309 published?

CVE-2015-6309 was published on 2015-10-02 and last updated on 2026-06-17.

CVE-2015-6309

CVE-2015-6309 is a medium-severity vulnerability in Cisco Email Security Appliance with a CVSS 2.0 base score of 6.8. 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-399.

Key facts

Severity: Medium (CVSS 2.0 base score 6.8)
EPSS exploit prediction: 2% (74th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-399
Affected product: Cisco Email Security Appliance
Published: 2015-10-02
Last modified: 2026-06-17

Description

Cisco Email Security Appliance (ESA) 8.5.6-106 and 9.6.0-042 allows remote authenticated users to cause a denial of service (file-descriptor consumption and device reload) via crafted HTTP requests, aka Bug ID CSCuw32211.

Frequently asked questions

What is CVE-2015-6309?: Cisco Email Security Appliance (ESA) 8.5.6-106 and 9.6.0-042 allows remote authenticated users to cause a denial of service (file-descriptor consumption and device reload) via crafted HTTP requests, aka Bug ID CSCuw32211.
How severe is CVE-2015-6309?: CVE-2015-6309 has a CVSS 2.0 base score of 6.8, rated medium severity.
Is CVE-2015-6309 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (74th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2015-6309?: CVE-2015-6309 primarily affects Cisco Email Security Appliance. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2015-6309?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2015-6309 published?: CVE-2015-6309 was published on 2015-10-02 and last updated on 2026-06-17.

References

Affected products (2)

cpe:2.3:h:cisco:email_security_appliance:9.6.0-042:*:*:*:*:*:*:*
cpe:2.3:o:cisco:email_security_appliance_firmware:8.5.6-106:*:*:*:*:*:*:*

More vulnerabilities in Cisco Email Security Appliance

CVE-2022-20798 — Critical (CVSS 9.8): A vulnerability in the external authentication functionality of Cisco Secure Email and Web Manager, formerly known as…
CVE-2019-1947 — High (CVSS 8.6): A vulnerability in the email message filtering feature of Cisco AsyncOS Software for Cisco Email Security Appliance…
CVE-2015-6321 — High (CVSS 7.8): Cisco AsyncOS before 8.5.7-042, 9.x before 9.1.0-032, 9.1.x before 9.1.1-023, and 9.5.x and 9.6.x before 9.6.0-042 on…
CVE-2015-6291 — High (CVSS 7.8): Cisco AsyncOS before 8.5.7-043, 9.x before 9.1.1-023, and 9.5.x and 9.6.x before 9.6.0-046 on Email Security Appliance…
CVE-2022-20664 — High (CVSS 7.7): A vulnerability in the web management interface of Cisco Secure Email and Web Manager, formerly Cisco Security…
CVE-2022-20960 — High (CVSS 7.5): A vulnerability in Cisco AsyncOS Software for Cisco Email Security Appliance (ESA) could allow an unauthenticated…

All CVEs affecting Cisco Email Security Appliance →

Other CWE-399 (Resource Management Errors) vulnerabilities

CVE-2015-8104 — Critical (CVSS 10.0): The KVM subsystem in the Linux kernel through 4.2.6, and Xen 4.3.x through 4.6.x, allows guest OS users to cause a…
CVE-2015-0339 — Critical (CVSS 10.0): Adobe Flash Player before 13.0.0.277 and 14.x through 17.x before 17.0.0.134 on Windows and OS X and before…
CVE-2015-0335 — Critical (CVSS 10.0): Adobe Flash Player before 13.0.0.277 and 14.x through 17.x before 17.0.0.134 on Windows and OS X and before…
CVE-2015-0333 — Critical (CVSS 10.0): Adobe Flash Player before 13.0.0.277 and 14.x through 17.x before 17.0.0.134 on Windows and OS X and before…
CVE-2014-4121 — Critical (CVSS 10.0): Microsoft .NET Framework 2.0 SP2, 3.5, 3.5.1, 4, 4.5, 4.5.1, and 4.5.2 does not properly parse internationalized…
CVE-2014-0560 — Critical (CVSS 10.0): Use-after-free vulnerability in Adobe Reader and Acrobat 10.x before 10.1.12 and 11.x before 11.0.09 on Windows and OS…

Browse all CWE-399 (Resource Management Errors) vulnerabilities →