How severe is CVE-2019-15971?

CVE-2019-15971 has a CVSS 3.x base score of 4.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is none, integrity low, and availability none.

Is CVE-2019-15971 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (36th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2019-15971?

CVE-2019-15971 affects Cisco Email Security Appliance Firmware. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2019-15971?

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

When was CVE-2019-15971 published?

CVE-2019-15971 was published on 2019-11-26 and last updated on 2026-06-17.

CVE-2019-15971

CVE-2019-15971 is a medium-severity vulnerability in Cisco Email Security Appliance Firmware with a CVSS 3.x base score of 4.3. 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-345.

Key facts

Severity: Medium (CVSS 3.x base score 4.3)
CVSS v2: 4.3
EPSS exploit prediction: 0% (36th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-345
Affected product: Cisco Email Security Appliance Firmware
Published: 2019-11-26
Last modified: 2026-06-17

Description

A vulnerability in the MP3 detection engine of Cisco AsyncOS Software for Cisco Email Security Appliance (ESA) could allow an unauthenticated, remote attacker to bypass configured content filters on the device. The vulnerability is due to improper validation of certain MP3 file types. An attacker could exploit this vulnerability by sending a crafted MP3 file through the targeted device. A successful exploit could allow the attacker to bypass configured content filters that would normally drop the email.

Frequently asked questions

What is CVE-2019-15971?: A vulnerability in the MP3 detection engine of Cisco AsyncOS Software for Cisco Email Security Appliance (ESA) could allow an unauthenticated, remote attacker to bypass configured content filters on the device. The vulnerability is due to improper validation of certain MP3 file types. An attacker could exploit this vulnerability by sending a crafted MP3 file through the targeted device. A successful exploit could allow the attacker to bypass configured content filters that would normally drop the email.
How severe is CVE-2019-15971?: CVE-2019-15971 has a CVSS 3.x base score of 4.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is none, integrity low, and availability none.
Is CVE-2019-15971 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (36th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2019-15971?: CVE-2019-15971 affects Cisco Email Security Appliance Firmware. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2019-15971?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2019-15971 published?: CVE-2019-15971 was published on 2019-11-26 and last updated on 2026-06-17.

References

https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20191120-esa-mp3-bypass

Affected products (1)

cpe:2.3:o:cisco:email_security_appliance_firmware:*:*:*:*:*:*:*:*

More vulnerabilities in Cisco Email Security Appliance Firmware

CVE-2016-6406 — Critical (CVSS 9.8): Cisco IronPort AsyncOS 9.1.2-023, 9.1.2-028, 9.1.2-036, 9.7.2-046, 9.7.2-047, 9.7.2-054, 10.0.0-124, and 10.0.0-125 on…
CVE-2018-15453 — High (CVSS 8.6): A vulnerability in the Secure/Multipurpose Internet Mail Extensions (S/MIME) Decryption and Verification or S/MIME…
CVE-2014-2119 — High (CVSS 8.5): The End User Safelist/Blocklist (aka SLBL) service in Cisco AsyncOS Software for Email Security Appliance (ESA) before…
CVE-2013-5537 — High (CVSS 7.8): The web framework on Cisco Web Security Appliance (WSA), Email Security Appliance (ESA), and Content Security…
CVE-2019-15961 — High (CVSS 7.5): A vulnerability in the email parsing module Clam AntiVirus (ClamAV) Software versions 0.102.0, 0.101.4 and prior could…
CVE-2019-12706 — High (CVSS 7.5): A vulnerability in the Sender Policy Framework (SPF) functionality of Cisco AsyncOS Software for Cisco Email Security…

All CVEs affecting Cisco Email Security Appliance Firmware →

Other CWE-345 (Insufficient Verification of Data Authenticity) vulnerabilities

CVE-2026-35051 — Critical (CVSS 10.0): Traefik is an HTTP reverse proxy and load balancer. Prior to versions 2.11.43, 3.6.14, and 3.7.0-rc.2, there is an…
CVE-2014-8165 — Critical (CVSS 10.0): scripts/amsvis/powerpcAMS/amsnet.py in powerpc-utils-python uses the pickle Python module unsafely, which allows remote…
CVE-2026-50195 — Critical (CVSS 9.9): containerd is an open-source container runtime. Versions prior to 2.3.2, 2.2.5 and 2.1.9 contain a vulnerability in the…
CVE-2022-36130 — Critical (CVSS 9.9): HashiCorp Boundary up to 0.10.1 did not properly perform data integrity checks to ensure the resources were associated…
CVE-2026-50214 — Critical (CVSS 9.8): The /v1/Plan service relies entirely on a shared global API token for full administrative management, allowing…
CVE-2025-15385 — Critical (CVSS 9.8): Insufficient Verification of Data Authenticity vulnerability in TECNO Mobile com.Afmobi.Boomplayer allows…

Browse all CWE-345 (Insufficient Verification of Data Authenticity) vulnerabilities →