CVE-2020-3181 | Cisco Email Security Appliance Uncontrolled Resource Exhaustion Vulnerability

A vulnerability in the malware detection functionality in Cisco Advanced Malware Protection (AMP) in Cisco AsyncOS Software for Cisco Email Security Appliances (ESAs) could allow an unauthenticated remote attacker to exhaust resources on an affected device. The vulnerability is due to insufficient control over system memory allocation. An attacker could exploit this vulnerability by sending a crafted email through the targeted device. A successful exploit could allow the attacker to cause an email attachment that contains malware to be delivered to a user and cause email processing delays.

Published: 2020-03-04 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2020-3181 is rated Moderate Risk (52/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 1.52%). Mandatory action: Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2020-3181

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.53% 1.52% +1.00%
2 2025-03-30 0.74% 0.53% -0.21%
3 2025-03-29 0.74%

Full EPSS history (11 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2020-3181

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.5 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:L)
Might cause slowdowns, glitches, or partial disruption—not a full brick.
3.9 2.5 [email protected]
6.5 3.0 MEDIUM
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:L)
Might cause slowdowns, glitches, or partial disruption—not a full brick.
3.9 2.5 [email protected]
6.4 2.0 MEDIUM
AV:N/AC:L/Au:N/C:N/I:P/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:P)
Partial availability impact.
10.0 4.9 [email protected]

Weakness enumeration for CVE-2020-3181

Affected software / configurations for CVE-2020-3181

Vendor Product Version Raw CPE
cisco email_security_appliance < 13.0.0 cpe:2.3:a:cisco:email_security_appliance:*:*:*:*:*:*:*:*

References for CVE-2020-3181

cvelogic Threat Intelligence