Threats / Exim / CVE-2019-10149
CVE-2019-10149
· EUVD no mirror located
· GCVE no mirror located
Verified 2026-08-04
Exim Mail Transfer Agent (MTA) vulnerability
Improper validation of recipient addresses in Exim's deliver_message() function allows remote command execution via shell metacharacter injection.
Verdict
Today item — known-exploited.
A remote attacker can execute arbitrary commands on systems running vulnerable Exim MTA instances by crafting malicious recipient addresses that bypass validation in the delivery processing logic.
CISA KEV Yes · 2022-01-105EPSS 0.99961 (verify live)6Exploit Weaponized · public PoC7CVSS 93CISA SSVC Exploitation: active · Automatable: no · Impact: total4
01
Is it exploitable?
— the evidence, ranked above the scoreExploit available
Fully weaponized — public exploit code is cataloged for this vulnerability.We link the existence of the exploit; we do not host or redistribute payloads.
Reported exploitation
12 independent public reports 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 2022-01-10).
Probability (EPSS)
EPSS 0.99961 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
CVSS 9 (CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H) · Affected: Exim, Mail Transfer Agent (MTA). Confirm exact fixed builds in the vendor advisory.CVSS — CNA-assigned (CVE.org), version 3.0, set at disclosure.
Weakness (CWE)
Mapped to CWE-78 OS Command Injection — weakness family: Injection.CWE — CNA-assigned (CVE.org); the weakness class drives how the flaw is exploited.
CISA SSVC (triage disposition)
Exploitation: active · Automatable: no · Technical Impact: totalCISA's own stakeholder-specific triage inputs, published in the CVE record (CISA Coordinator role). NOTE: this is CISA's three decision points; the final Act/Attend/Track decision also requires a Mission & Well-being input not published here, so no overall decision is asserted.
Currency of the record
CISA added this to its KEV catalog 950 days after the CVE record was published.KEV lag = CISA-KEV dateAdded − CVE.org datePublished; a floor on how long the known-exploited flaw sat in the public record before the federal catalog listed it. Severity/weakness here is CNA- or CISA-assigned (current at disclosure), independent of NVD's analysis backlog.
Public exploit available
Public exploit tooling is catalogued for this CVE (a functional/weaponized public exploit). Catalog entries: Metasploit module. We link the catalog page(s) only — no payload or code is hosted or restated here.Link, never host — the catalog page is the source; basicsecurity.net does not redistribute payloads.
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
Craft a message with a specially-formed recipient address containing shell metacharacters that evade validation checks.
Business
Attacker gains code execution with the privileges of the Exim process, typically root or a dedicated mail user.
2
Keys to the kingdom — privilege/identity takeover narrative 2
Attacker
Inject commands through the unvalidated recipient field to execute arbitrary system operations during message delivery.
Business
Compromised mail server becomes a pivot point for lateral movement, data exfiltration, or further infrastructure compromise.
3
Lateral reach — past segmentation narrative 3
Attacker
Establish persistence or deploy malware on the affected mail transfer agent.
Business
Organization loses control of critical email infrastructure and faces potential data breach, service disruption, and regulatory exposure.
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