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CVE Record

CVE-2019-19920: sa-exim 4.2.1 allows attackers to execute arbitrary code if they can write a .cf file or a rule.

sa-exim 4.2.1 allows attackers to execute arbitrary code if they can write a .cf file or a rule. This occurs because Greylisting.pm relies on eval (rather than direct parsing and/or use of the taint feature). This issue is similar to CVE-2018-11805.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

CVE-2019-19920 affects sa-exim 4.2.1. If an attacker can place or modify a configuration file or SpamAssassin rule processed by sa-exim greylisting logic, the software may execute attacker-controlled code. This is serious where mail filtering configuration is writable by untrusted users or compromised automation.

Executive priority

Treat this as priority remediation for mail gateways using sa-exim. The impact is arbitrary code execution, but the known attack path requires configuration or rule write access, so urgency depends on local permissions and operational controls.

Technical view

Greylisting.pm in sa-exim 4.2.1 uses Perl eval for configuration or rule handling instead of safer parsing or taint protections. The CVE states this can allow arbitrary code execution when an attacker can write a .cf file or rule. Debian and Ubuntu issued security updates for sa-exim.

Likely exposure

Exposure is most likely on Debian or Ubuntu systems running sa-exim with SpamAssassin integration, especially mail gateways where rule or .cf file writes are delegated, automated, or insufficiently restricted.

Exploitation context

The provided sources do not show active exploitation, and CISA KEV status is false. The key precondition is write access to a .cf file or rule consumed by sa-exim; without that, exploitation evidence is incomplete.

Researcher notes

The source bundle names sa-exim 4.2.1 and Greylisting.pm eval behavior, but does not provide CVSS, CWE, exploit details, or broad affected-version ranges. Do not assume remote unauthenticated exploitation from these sources alone.

Mitigation direction

  • Apply the Debian or Ubuntu sa-exim security update where applicable.
  • Check upstream or distribution guidance for non-Debian and non-Ubuntu deployments.
  • Restrict write access to SpamAssassin rule and .cf directories.
  • Review automation that updates mail filtering rules or greylisting configuration.
  • Monitor mail gateway integrity for unexpected rule or configuration changes.

Validation and detection

  • Identify systems with sa-exim installed and record package versions.
  • Confirm whether sa-exim 4.2.1 is present or patched by the distribution.
  • Verify file permissions on SpamAssassin rule and .cf locations.
  • Review recent changes to greylisting and mail filtering configuration.
  • Check package advisory references against installed Debian or Ubuntu builds.
Prepared
Confidence
medium
Sources
5

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

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ATT&CK lookup starting points

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description · low confidence lookup

Execution behavior lookup

The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.

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CVE-2019-19920 mapping review

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Vulnerability profileCVE Program record
Severity
Unknown
CVSS
Not scored
Known Exploited
No
Published
Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

0CVSS vectors
0Timeline events
0ADP providers
6Source links

CVSS and timeline data

No CVSS vectors or timeline events were available in the normalized CVE source material.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
n/an/an/aListed
Weakness

CWE details

No CWE listed

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.