CVE-2020-27840
Spaces used in a string around a domain name (DN), while supposed to be ignored, can cause invalid DN strings with spaces to instead write a zero-byte into out-of-bounds memory, resulting in a crash.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (3.83%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
A flaw was found in samba. Spaces used in a string around a domain name (DN), while supposed to be ignored, can cause invalid DN strings with spaces to instead write a zero-byte into out-of-bounds memory, resulting in a crash. The highest threat from this vulnerability is to system availability.
- CVSS 3.1
- 7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- EPSS
- 3.83% probability · 90th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-125
- Affected
- samba/samba · debian/debian linux · fedoraproject/fedora
- Source
- secalert@redhat.com
EPSS 3.8% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://bugzilla.redhat.com/show_bug.cgi?id=1941400Issue Tracking, Third Party Advisory
- https://lists.debian.org/debian-lts-announce/2021/03/msg00036.htmlMailing List, Third Party Advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/VLZ74IF2N75VQSIHBL4B3P5WKWQCXSRY/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/X5J3B6PN5XMXF3OHYBNHDKZ3XFSUGY4L/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZXP3ONIY6MB4C5LDZV4YL5KJCES3UX24/
- https://security.gentoo.org/glsa/202105-22Third Party Advisory
- https://security.netapp.com/advisory/ntap-20210326-0007/Third Party Advisory
- https://www.debian.org/security/2021/dsa-4884Third Party Advisory
- https://www.samba.org/samba/security/CVE-2020-27840.htmlVendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=1941400Issue Tracking, Third Party Advisory
- https://lists.debian.org/debian-lts-announce/2021/03/msg00036.htmlMailing List, Third Party Advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/VLZ74IF2N75VQSIHBL4B3P5WKWQCXSRY/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/X5J3B6PN5XMXF3OHYBNHDKZ3XFSUGY4L/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZXP3ONIY6MB4C5LDZV4YL5KJCES3UX24/
- https://security.gentoo.org/glsa/202105-22Third Party Advisory
- https://security.netapp.com/advisory/ntap-20210326-0007/Third Party Advisory
- https://www.debian.org/security/2021/dsa-4884Third Party Advisory
- https://www.samba.org/samba/security/CVE-2020-27840.htmlVendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.