CVE-2018-6789: Exim Buffer Overflow Vulnerability

CVE-2018-6789 · Severity: critical · CVSS 9.8 · Exploited in the wild · Published 2021-11-03

Exim contains a buffer overflow vulnerability in the base64d function of its SMTP listener. By sending a handcrafted message, a remote attacker can trigger the overflow to execute arbitrary code.

Technologies: Exim. Vendors: Exim.

Quick answers

Is CVE-2018-6789 exploited in the wild?
Yes. CVE-2018-6789 is known to be exploited in the wild, first recorded on 3 November 2021. Treat it as urgent.
How severe is CVE-2018-6789?
Critical severity, with a CVSS score of 9.8, published 3 November 2021.
Which products and versions are affected?
Exim Exim before 4.90.1; Canonical Ubuntu Linux 14.04, 16.04, 17.10; Debian Debian Linux.
Is there a fix for CVE-2018-6789?
A patch was published on 2018-02-05: Patch committed to Exim git repository. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2018-6789 attacked?
It is attacked over the network, in a hosted service.
Am I affected by CVE-2018-6789?
Check whether you run Exim. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Affected products

  • Exim Exim before 4.90.1
  • Canonical Ubuntu Linux 14.04, 16.04, 17.10
  • Debian Debian Linux

Timeline

  • 2018-02-05: patched: Patch committed to Exim git repository.
  • 2018-02-07: disclosed: Initial disclosure on OSS-security mailing list.
  • 2021-11-03: kev added: Added to CISA Known Exploited Vulnerabilities Catalog.

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