cbcvebase.
CVE-2019-16928
published 2019-09-27

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…

PriorityP185critical9.8CVSS 3.1
AVNACLPRNUINSUCHIHAH
KEVITW
CISA Known Exploited Vulnerabilitydue 2022-03-17
Exploited in the wild
EPSS
42.48%
98.5th percentile
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.

Affected

7 ranges
VendorProductVersion rangeFixed in
canonicalubuntu_linux
debiandebian_linux
debianexim4< exim4 4.92.2-3 (bookworm)exim4 4.92.2-3 (bookworm)
eximexim4.92 – 4.92.2
fedoraprojectfedora
fedoraprojectfedora
fedoraprojectfedora

Detection & IOCsextracted from sources · hover to see the quote

commandEHLO <large crafted string>
  • Trend Micro Deep Discovery Inspector rule for detecting CVE-2019-16928 exploit attempts over SMTP
  • Trend Micro Deep Security Deep Packet Inspection rule for CVE-2019-16928
  • Trend Micro TippingPoint MainlineDV filter for CVE-2019-16928 SMTP buffer overflow
  • The vulnerability is triggered via an oversized EHLO string sent to the Exim SMTP listener; monitor for abnormally long EHLO commands in SMTP traffic
  • A proof-of-concept exploit is publicly available (shipped with the patch) that causes a DoS condition; expect active scanning of Exim SMTP services
  • ·No authentication is required to exploit this vulnerability; the attacker only needs network access to the SMTP port

CVSS provenance

nvdv3.19.8CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
nvdv2.07.5HIGHAV:N/AC:L/Au:N/C:P/I:P/A:P
osv9.8CRITICAL
vulncheck9.8CRITICAL
cisa9.8CRITICAL
vendor_debian9.8CRITICAL
vendor_redhat9.8CRITICAL
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