CVE-2020-3134
Cisco Email Security Appliance Zip Decompression Engine Denial of Service Vulnerability
A vulnerability in the zip decompression engine of Cisco AsyncOS Software for Cisco Email Security Appliance (ESA) could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to improper validation of zip files. An attacker could exploit this vulnerability by sending an email message with a crafted zip-compressed attachment. A successful exploit could trigger a restart of the content-scanning process, causing a temporary DoS condition. This vulnerability affects Cisco AsyncOS Software for Cisco ESA releases earlier than 13.0.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- Low
- Availability
- Low
Exploit likelihood
What each source reports
CVE List Score used
Cisco Email Security Appliance Zip Decompression Engine Denial of Service Vulnerability
A vulnerability in the zip decompression engine of Cisco AsyncOS Software for Cisco Email Security Appliance (ESA) could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to improper validation of zip files. An attacker could exploit this vulnerability by sending an email message with a crafted zip-compressed attachment. A successful exploit could trigger a restart of the content-scanning process, causing a temporary DoS condition. This vulnerability affects Cisco AsyncOS Software for Cisco ESA releases earlier than 13.0.
- Record
CVE-2020-3134- CVSS 3.0
- 6.5 Medium
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L - Weakness
- CWE-20
- Updated
- 2026-11-02
EUVDEUVD-2020-24405
A vulnerability in the zip decompression engine of Cisco AsyncOS Software for Cisco Email Security Appliance (ESA) could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to improper validation of zip files. An attacker could exploit this vulnerability by sending an email message with a crafted zip-compressed attachment. A successful exploit could trigger a restart of the content-scanning process, causing a temporary DoS condition. This vulnerability affects Cisco AsyncOS Software for Cisco ESA releases earlier than 13.0.
- Record
EUVD-2020-24405- CVSS 3.0
- 6.5 Medium
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L - Updated
- 2026-11-03
GitHub AdvisoriesGHSA-gf7w-86p9-r93x
[CVE-2020-3134_su] A vulnerability in the zip decompression engine of Cisco AsyncOS Software for...
[CVE-2020-3134_su] A vulnerability in the zip decompression engine of Cisco AsyncOS Software for Cisco Email Security Appliance (ESA) could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to improper validation of zip files. An attacker could exploit this vulnerability by sending an email message with a crafted zip-compressed attachment. A successful exploit could trigger a restart of the content-scanning process, causing a temporary DoS condition.
- Record
GHSA-gf7w-86p9-r93x- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L - Weakness
- CWE-20
- Updated
- 2026-11-02
NVD
A vulnerability in the zip decompression engine of Cisco AsyncOS Software for Cisco Email Security Appliance (ESA) could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to improper validation of zip files. An attacker could exploit this vulnerability by sending an email message with a crafted zip-compressed attachment. A successful exploit could trigger a restart of the content-scanning process, causing a temporary DoS condition. This vulnerability affects Cisco AsyncOS Software for Cisco ESA releases earlier than 13.0.
- Record
CVE-2020-3134- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L - CVSS 3.0
- 6.5 Medium
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L - CVSS 2.0
- 6.4 Medium
AV:N/AC:L/Au:N/C:N/I:P/A:P - Weakness
- CWE-20
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases, published | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2020-3134 is a medium vulnerability (CVSS 6.5) in Cisco Email Security Appliance (esa), published January 26, 2020. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.09%, the 65th percentile. No source names a fixed version.