CVE-2020-27840: debian debian_linux Out-of-bounds Read
Vulnerability summary
CVE-2020-27840 is a high (CVSS 7.5) Out-of-bounds Read vulnerability in debian debian_linux. EPSS estimates a 3.83% chance of exploitation in the next 30 days, higher than 90.1% of scored vulnerabilities.
Severe, CVSS 7.5 (NVD); no exploitation reported by the 5 checked sources; EPSS 4% (FIRST, 03-11-2026)
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 18 · Related 15Timeline
- 12-05-2021PublishedVulnerability first disclosed.
- 04-08-2024Last modifiedVulnerability information updated.
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 metrics
5 scores · 4 sources · 2 versions- OSV · AlpineEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- OSV · UbuntuEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- OSV · DebianEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS trend
Probability
3.83%
Chance of exploitation in the next 30 days
Percentile
90%
Versus all other CVEs
30-day change
No change 0.00 pp
From 3.83% on 04-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.
Debian2 products
- samba< 2:4.13.13+dfsg-1
- debian_linuxEOL9.0 | 10.0
Alpine1 product
- samba≥ 4.0.0, < 4.12.14-r0 | ≥ 4.0.0, < 4.13.7-r0 | ≥ 4.0.0, < 4.14.2-r0
Fedoraproject1 product
- fedoraEOL32 | 33 | 34
Samba1 product
- samba≥ 4.0.0, < 4.12.13 | ≥ 4.13.0, < 4.13.6 | ≥ 4.14.0, < 4.14.1
Ubuntu1 product
- ldb< 1:1.1.24-0ubuntu0.14.04.2+esm1 | < 2:1.1.24-1ubuntu3.2 | < 2:1.2.3-1ubuntu0.2 | < 2:2.0.10-0ubuntu0.20.04.3
5 vendors · 6 products
References
16 links
lists.debian.org/debian-lts-announce/2021/03/msg00036.htmlMailing ListX Refsource MLISTThird Party Advisory
