CVE-2020-14871
CVE-2020-14871 is a security flaw in Oracle Solaris and Zettabyte File System (ZFS). Attackers are using a flaw in Oracle Solaris and Zettabyte File System (ZFS) that its maker hasn't described in detail. The US Cybersecurity and Infrastructure Security Agency (CISA) added it to its catalog of flaws known to be used in attacks on 3 Nov 2021.[1]
Oracle Solaris and Zettabyte File System (ZFS) is business software or equipment. Most families won’t have it, but attackers break into it to get inside companies, and from there to what those companies hold about their customers, patients and staff. Oracle has published a fix or advice.
Description
CISA calls it an unspecified in Oracle Solaris and Zettabyte File System (ZFS). In its words: “Oracle Solaris and Oracle ZFS Storage Appliance Kit contain an unspecified vulnerability causing high impacts to confidentiality, integrity, and availability of affected systems.”[1]
The CVE record adds: “Vulnerability in the Oracle Solaris product of Oracle Systems (component: Pluggable authentication module). Supported versions that are affected are 10 and 11. Easily exploitable vulnerability allows unauthenticated attacker with network access via multiple protocols to compromise Oracle Solaris. While the vulnerability is in Oracle Solaris, attacks may significantly impact additional products. Successful attacks of this vulnerability can result in takeover of Oracle Solaris. Note: This CVE is not exploitable for Solaris 11.1 and later releases, and ZFSSA 8.7 and later releases, thus the CVSS Base Score is 0.0. CVSS 3.1 Base Score 10.0 (Confidentiality, Integrity and Availability impacts). CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H).”[2]
The underlying weakness is out-of-bounds write (CWE-787), in MITRE’s list of common software weaknesses.
It scores 10.0 out of 10 on the Common Vulnerability Scoring System, which rates it critical, scored by the organisation that published the CVE using CVSS 3.1.[2]
Affected versions
NVD’s record doesn’t list version ranges for it; Oracle’s advisory has them[3]. CISA names the product as Oracle Solaris and Zettabyte File System (ZFS).
Most families won’t have Oracle Solaris and Zettabyte File System (ZFS); it’s for whoever looks after IT at work.
Exploitation
CISA added it to its catalog of known exploited vulnerabilities on 3 Nov 2021, 378 days after it was made public. CISA lists a flaw only when it has reliable evidence of it being exploited, and gave US federal agencies until 3 May 2022 to fix it.[1]
FIRST’s Exploit Prediction Scoring System, which estimates how likely a flaw is to be used in attacks in the next 30 days from what it sees across the internet, puts it at 80%. That’s in the top 1% of the flaws it scores.[4]
CISA assesses it as not automatable: each attack takes some work.
CISA doesn’t say who was attacked, or how.
Fix
Oracle has published a fix or advice.[3] CISA’s required action: “Apply updates per vendor instructions.”[1]
- Check whether you use it.Oracle Solaris and Zettabyte File System (ZFS) is business software or equipment, so most families won’t have it. If you run a business, or work from home on company equipment, ask whoever looks after your IT.
- Send this page to your IT person.Ask them to confirm it’s fixed, or not in use. CISA gave US government agencies until 3 May 2022 to fix it.
- If it can’t be fixed, take it offline.CISA’s advice when there’s no fix is to stop using the product, or take it off the internet, until there is one.
You can’t fix someone else’s server, but you can watch for what follows a break-in like this: a breach notice, a password reset you didn’t ask for, or a scam message that knows things it shouldn’t. HARD watches for those for you and your family.
Timeline
| Date | Event |
|---|---|
| The flaw is made public in the National Vulnerability Database, with a severity score of 10.0.[2] | |
| CISA adds it to its catalog of flaws known to be used in attacks.[1] | |
| CISA’s deadline for US government agencies to fix it.[1] | |
| FIRST puts the odds of it being used in attacks in the next 30 days at 80%.[4] |
See also
Other Oracle flaws
- CVE-2026-21962, Oracle HTTP Server and Oracle Weblogic Server Proxy Plug-in: improper access control ·
- CVE-2026-46817, Oracle E-Business Suite: improper privilege management ·
- CVE-2026-35273, Oracle PeopleSoft Enterprise PeopleTools: missing authentication for critical function ·
- CVE-2024-21182, Oracle WebLogic Server: unspecified ·
- CVE-2025-61757, Oracle Fusion Middleware: missing authentication for critical function ·
Other out-of-bounds write flaws
- CVE-2026-86950, Apple devices: out-of-bounds write ·
- CVE-2026-53266, Linux Kernel: out-of-bounds write ·
- CVE-2026-87491, Chrome and other Chromium browsers: out of bounds write ·
- CVE-2026-53362, Linux Kernel: unspecified ·
- CVE-2022-0995, Linux Kernel: out-of-bounds write ·
Added the same day
- CVE-2021-42258, BQE BillQuick Web Suite: SQL injection ·
- CVE-2021-42013, Apache HTTP Server: path traversal ·
- CVE-2021-41773, Apache HTTP Server: path traversal ·
- CVE-2021-40539, Zoho ManageEngine: aDSelfService plus authentication bypass ·
- CVE-2021-40444, Microsoft MSHTML: remote code execution ·
Every Oracle flaw on CISA’s list · Everything added in November 2021
References
- ^ Cybersecurity and Infrastructure Security Agency. “Oracle Solaris and Zettabyte File System (ZFS) Unspecified Vulnerability”. Known Exploited Vulnerabilities Catalog, added 3 Nov 2021.
- ^ National Institute of Standards and Technology. “CVE-2020-14871 Detail”. National Vulnerability Database, published 21 Oct 2020.
- ^ Oracle. Advisories and fixes: oracle.com.
- ^ FIRST. “Exploit Prediction Scoring System”. EPSS 0.802, percentile 99.6, 31 Oct 2026.
- CVE Program. “CVE-2020-14871”. The official CVE record.
This article is built from CISA’s catalog (version 2026.10.30), NVD’s record and FIRST’s scores, kept in HARD’s database and checked every morning. The plain English is HARD’s.