Threats / Exim / CVE-2019-16928
CVE-2019-16928
· EUVD no mirror located
· GCVE no mirror located
Verified 2026-06-22
Exim Internet Mailer vulnerability
Exim Internet Mailer contains an out-of-bounds write vulnerability (CWE-787) enabling remote code execution. The flaw has been exploited in the wild.
Verdict
Today item — known-exploited.
An unauthenticated remote attacker can exploit this out-of-bounds write to achieve arbitrary code execution on systems running vulnerable Exim versions. Active exploitation in the wild indicates immediate risk to mail infrastructure.
01
Is it exploitable?
— the evidence, ranked above the scoreReported exploitation
1 independent public report of in-the-wild exploitation are cataloged.Distinct reporting sources (vendor, incident response, government); open them for the underlying claims.
Exploited in the wild
Listed in the CISA Known Exploited Vulnerabilities catalog (added 2022-03-03).
Probability (EPSS)
EPSS 0.42482 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
Affected: Exim, Exim Internet Mailer. Confirm exact fixed builds in the vendor advisory.
Weakness (CWE)
Mapped to CWE-787 Out-of-bounds Write — weakness family: Memory safety.CWE assignment from the public NVD record; the weakness class drives how the flaw is exploited.
02
Who’s exploiting it?
— attribution turns risk into urgencyAttribution not established
No confirmed (advisory-backed) threat-actor attribution is established for this record. Absence of a named actor is not absence of compromise — see Coverage & confidence.
03
Why it matters
— the attack path, told twice: adversary, then board1
Front door — unauthenticated access narrative 1
Attacker
I craft a malicious message or SMTP command that triggers an out-of-bounds write in Exim's memory handling.
Business
Mail server is compromised, enabling attacker to read, modify, or delete email and access internal communications.
2
Keys to the kingdom — privilege/identity takeover narrative 2
Attacker
I execute arbitrary code with the privileges of the Exim process to establish persistence and lateral movement.
Business
Attacker gains foothold in network infrastructure, potentially compromising connected systems and sensitive data.
3
Lateral reach — past segmentation narrative 3
Attacker
I use the compromised mail server to distribute malware, phishing campaigns, or further attacks against downstream recipients.
Business
Organization's reputation is damaged; customers and partners receive malicious content originating from trusted mail infrastructure.
04
What to do
— defensible action- Remediate per the vendor advisory — confirm the fixed build for your version and verify exposure.1
Say it to the boardA vulnerability with this evidence profile is a defensible budget line, not a backlog ticket — fund the change against the proof above.
05