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.
Does this matter?
EPSS puts the probability of exploitation in the next 30 days at 88.9%, higher than 100% of all known CVEs. Patch or mitigate before the next change window.
Description
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 because the server code launches the client code during bounce handling.
- CVSS 3.1
- 9.8 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 88.90% probability · 100th percentile
- Public exploits
- 2 in Exploit-DB · verified · first 26 February 2020
- CISA KEV
- Not listed
- Weakness
- CWE-125
- Affected
- opensmtpd/opensmtpd · canonical/ubuntu linux · fedoraproject/fedora · debian/debian linux
- Source
- cve@mitre.org
EPSS 88.9% since 3 November 2026; no change recorded yet. The dashed line is the ten per cent mark our analysts treat as “patch before the next change window”. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
Public exploits (2)
Entries in Exploit-DB that cite this CVE. Links go to the Exploit-DB page and to the file in the public repository; nothing is hosted here. A verified tick means the Exploit-DB team confirmed the exploit works against the stated version.
References
- http://packetstormsecurity.com/files/156633/OpenSMTPD-Out-Of-Bounds-Read-Local-Privilege-Escalation.htmlExploit, Third Party Advisory, VDB Entry
- http://seclists.org/fulldisclosure/2020/Feb/32Mailing List, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2020/02/26/1Exploit, Mailing List, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2020/03/01/1Mailing List, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2020/03/01/2Mailing List, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2021/05/04/7Exploit, Mailing List, Third Party Advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/OPH4QU4DNVHA7ACFXMYFCEP5PSXXPN4E/
- https://usn.ubuntu.com/4294-1/Patch, Third Party Advisory
- https://www.debian.org/security/2020/dsa-4634Third Party Advisory
- https://www.openbsd.org/security.htmlThird Party Advisory
- https://www.openwall.com/lists/oss-security/2020/02/24/5Exploit, Mailing List, Third Party Advisory
- http://packetstormsecurity.com/files/156633/OpenSMTPD-Out-Of-Bounds-Read-Local-Privilege-Escalation.htmlExploit, Third Party Advisory, VDB Entry
- http://seclists.org/fulldisclosure/2020/Feb/32Mailing List, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2020/02/26/1Exploit, Mailing List, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2020/03/01/1Mailing List, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2020/03/01/2Mailing List, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2021/05/04/7Exploit, Mailing List, Third Party Advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/OPH4QU4DNVHA7ACFXMYFCEP5PSXXPN4E/
- https://usn.ubuntu.com/4294-1/Patch, Third Party Advisory
- https://www.debian.org/security/2020/dsa-4634Third Party Advisory
- https://www.openbsd.org/security.htmlThird Party Advisory
- https://www.openwall.com/lists/oss-security/2020/02/24/5Exploit, Mailing List, Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.