CVE-2019-1933 | Cisco Email Security Appliance Content Filter Bypass Vulnerability

A vulnerability in the email message scanning of Cisco AsyncOS Software for Cisco Email Security Appliance (ESA) could allow an unauthenticated, remote attacker to bypass configured filters on the device. The vulnerability is due to improper input validation of certain email fields. An attacker could exploit this vulnerability by sending a crafted email message to a recipient protected by the ESA. A successful exploit could allow the attacker to bypass configured message filters and inject arbitrary scripting code inside the email body. The malicious code is not executed by default unless the recipient's email client is configured to execute scripts contained in emails.

Published: 2019-07-05 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2019-1933 is rated Moderate Risk (47/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 1.24%). Core evidence: EPSS rose +1.04% over the last day, indicating growing attacker interest. 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-2019-1933

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 0.20% 1.24% +1.04%
2 2025-03-17 0.12% 0.20% +0.08%
3 2023-03-07 0.12%

Full EPSS history (7 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2019-1933

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.8 3.0 MEDIUM
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N 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:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
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:N)
Service keeps running; no real outage angle.
3.9 1.4 [email protected]
7.4 3.0 HIGH
CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:H/A:N 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:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:N)
Service keeps running; no real outage angle.
2.8 4.0 [email protected]
4.3 2.0 MEDIUM
AV:N/AC:M/Au:N/C:N/I:P/A:N Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:N)
No availability impact.
8.6 2.9 [email protected]

Weakness enumeration for CVE-2019-1933

Affected software / configurations for CVE-2019-1933

Vendor Product Version Raw CPE
cisco email_security_appliance 11.1.2-023 cpe:2.3:a:cisco:email_security_appliance:11.1.2-023:*:*:*:*:*:*:*

References for CVE-2019-1933

cvelogic Threat Intelligence