Buffer overflow in Exim

CVE-2019-16928

Exim 4.92 through 4.92.2 allows remote code execution, a different vulnerability than CVE-2019-15846. There is a heap-based buffer overflow in string_vformat in string.c involving a long EHLO command.

Vulnerability class: Buffer Overflow

EPSS: 0.416 (98.5th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Affected products

Weakness classification (CWE)

CISA KEV (Known Exploited Vulnerabilities)

This CVE is on the CISA KEV catalog, added on . CISA KEV inclusion means CISA has confirmed in-the-wild exploitation; US federal agencies are required to remediate within a published due date.

BOD 22-01 due date: .

Required action: Apply updates per vendor instructions.

Public proof-of-concept exploits

References

  • cve@mitre.org (x_refsource_MISC, Vendor Advisory)
  • cve@mitre.org (Patch, x_refsource_MISC, Issue Tracking, Vendor Advisory)
  • cve@mitre.org (Patch, x_refsource_MISC)
  • cve@mitre.org (mailing-list, x_refsource_MLIST, Exploit, Mailing List, Third Party Advisory, Mitigation)
  • cve@mitre.org (mailing-list, x_refsource_MLIST, Exploit, Mailing List, Third Party Advisory)
  • cve@mitre.org (mailing-list, x_refsource_MLIST, Mailing List, Third Party Advisory)
  • cve@mitre.org (vendor-advisory, Third Party Advisory, x_refsource_DEBIAN)
  • cve@mitre.org (x_refsource_UBUNTU, vendor-advisory, Third Party Advisory)
  • cve@mitre.org (mailing-list, x_refsource_MLIST, Mailing List, Third Party Advisory)
  • cve@mitre.org (mailing-list, x_refsource_BUGTRAQ, Mailing List, Third Party Advisory)

Frequently asked questions

What is CVE-2019-16928?
CVE-2019-16928 is a critical-severity vulnerability in Exim, classified under Out-of-bounds Write. CVSS score: 9.8/10. Published 2019-09-27.
How severe is CVE-2019-16928?
Critical severity. CVSS v3 base score is 9.8 out of 10.
Is CVE-2019-16928 known to be exploited?
Yes. CVE-2019-16928 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2022-03-03), indicating it is being actively exploited. 10 public proof-of-concept repositories are indexed.