CVE-2019-10149VulnerabilityPublished 01/10/2022Updated 10/24/2026

CVE-2019-10149: Exim Mail Transfer Agent (MTA) Improper Input Validation

Affects Exim Mail Transfer Agent (MTA)Source CISA KEV

Severity

High

No CVSS score published yet

Exploitation: Actively exploited – in CISA KEV since 01/10/2022
KEV deadline: 07/10/2022
EPSS: 100.0% chance of exploitation in 30 days – higher than 99% of CVEs

What to do

CISA required action

Apply updates per vendor instructions.

nvd.nist.gov/vuln/detail/CVE-2019-10149 (opens in a new tab)

Description

CVE-2019-10149 is a high severity vulnerability in the Exim Mail Transfer Agent (MTA) involving improper validation of recipient addresses in the deliver_message() function. This flaw can lead to remote command execution by an attacker. The vulnerability has been exploited in the wild. No specific affected versions or patch information is provided in the input data.

Summary

The vulnerability CVE-2019-10149 in Exim MTA arises from improper input validation of recipient addresses within the deliver_message() function in the source file /src/deliver.c. This flaw allows remote attackers to execute arbitrary commands on the affected system. The issue is classified under CWE-78 (Improper Neutralization of Special Elements used in an OS Command). Exploitation of this vulnerability has been observed in the wild, indicating active threat usage.

Impact

Successful exploitation of this vulnerability enables remote command execution on the affected Exim MTA server, potentially allowing attackers to take full control of the system. This can lead to unauthorized access, data compromise, and further network penetration.

Mitigation

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is confirmed, it is recommended to monitor vendor communications for patches or workarounds. Given the known exploitation in the wild, applying vendor-provided updates or mitigations promptly is critical once available.

Weaknesses

CWE-78OS Command Injection (opens in a new tab)

What to do

Description

AnalysisAI-generated, updated 10/24/2026, 09:56:27 UTC

Weaknesses

References

Related threats