Out-of-bounds Read in Opensmtpd

CVE-2020-8794

OpenSMTPD before 6.6.4 allows remote code execution because of an out-of-bounds read in mta_io in mta_session.c for multi-line replies. Although this vulnerability affects the client side of OpenSMTPD, it is possible to attack a server bec…

Vulnerability class: Buffer Overflow

EPSS: 0.889 (99.8th 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)

Public proof-of-concept exploits

References

  • cve@mitre.org (Third Party Advisory, x_refsource_MISC)
  • cve@mitre.org (Exploit, Mailing List, Third Party Advisory, x_refsource_MISC)
  • cve@mitre.org (mailing-list, x_refsource_MLIST, Exploit, Mailing List, Third Party Advisory)
  • cve@mitre.org (vendor-advisory, Third Party Advisory, x_refsource_DEBIAN)
  • cve@mitre.org (mailing-list, x_refsource_FULLDISC, Mailing List, Third Party Advisory)
  • cve@mitre.org (mailing-list, x_refsource_MLIST, Mailing List, Third Party Advisory)
  • cve@mitre.org (mailing-list, x_refsource_MLIST, Mailing List, Third Party Advisory)
  • cve@mitre.org (Exploit, VDB Entry, Third Party Advisory, x_refsource_MISC)
  • cve@mitre.org (x_refsource_FEDORA, vendor-advisory)
  • cve@mitre.org (x_refsource_UBUNTU, vendor-advisory, Patch, Third Party Advisory)

Frequently asked questions

What is CVE-2020-8794?
CVE-2020-8794 is a critical-severity vulnerability in Opensmtpd, classified under Out-of-bounds Read. CVSS score: 9.8/10. Published 2020-02-25.
How severe is CVE-2020-8794?
Critical severity. CVSS v3 base score is 9.8 out of 10.
Is CVE-2020-8794 known to be exploited?
24 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.