CVE-2021-35587
CVE-2021-35587 is a security flaw in Oracle Fusion Middleware, Oracle’s business software. Attackers are using a flaw in Oracle Fusion Middleware 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 28 Nov 2022.[1]
Oracle Fusion Middleware 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 Fusion Middleware. In its words: “Oracle Fusion Middleware Access Manager allows an unauthenticated attacker with network access via HTTP to takeover the Access Manager product.”[1]
The CVE record adds: “Vulnerability in the Oracle Access Manager product of Oracle Fusion Middleware (component: OpenSSO Agent). Supported versions that are affected are 11.1.2.3.0, 12.2.1.3.0 and 12.2.1.4.0. Easily exploitable vulnerability allows unauthenticated attacker with network access via HTTP to compromise Oracle Access Manager. Successful attacks of this vulnerability can result in takeover of Oracle Access Manager. CVSS 3.1 Base Score 9.8 (Confidentiality, Integrity and Availability impacts). CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H).”[2]
The underlying weakness is deserialization of untrusted data (CWE-502), CWE-790, in MITRE’s list of common software weaknesses.
It scores 9.8 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 Fusion Middleware.
Most families won’t have Oracle Fusion Middleware; it’s for whoever looks after IT at work.
Exploitation
CISA added it to its catalog of known exploited vulnerabilities on 28 Nov 2022, 313 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 19 Dec 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 96%. That’s in the top 1% of the flaws it scores.[4]
CISA assesses it as automatable: attackers can run it against many targets at once.
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 Fusion Middleware 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 19 Dec 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 9.8.[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 96%.[4] |
See also
Other Oracle Fusion Middleware flaws
- CVE-2025-61757: missing authentication for critical function ·
- CVE-2020-2551: unspecified ·
- CVE-2012-1710: unspecified ·
- CVE-2012-0518: unspecified ·
- CVE-2012-3152: unspecified ·
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-2025-61884, Oracle E-Business Suite: server-side request forgery (SSRF) ·
Other deserialization of untrusted data flaws
- CVE-2021-23758, Ajax.NET Professional: deserialization of untrusted data ·
- CVE-2026-63077, JetBrains TeamCity: deserialization of untrusted data ·
- CVE-2026-50522, Microsoft SharePoint: deserialization of untrusted data ·
- CVE-2026-58644, Microsoft SharePoint: deserialization of untrusted data ·
- CVE-2026-45659, Microsoft SharePoint Server: deserialization of untrusted data ·
Added the same day
- CVE-2022-4135, Chrome and other Chromium browsers: heap buffer overflow ·
Every Oracle flaw on CISA’s list · Everything added in November 2022
References
- ^ Cybersecurity and Infrastructure Security Agency. “Oracle Fusion Middleware Unspecified Vulnerability”. Known Exploited Vulnerabilities Catalog, added 28 Nov 2022.
- ^ National Institute of Standards and Technology. “CVE-2021-35587 Detail”. National Vulnerability Database, published 19 Jan 2022.
- ^ Oracle. Advisories and fixes: oracle.com.
- ^ FIRST. “Exploit Prediction Scoring System”. EPSS 0.963, percentile 99.9, 31 Oct 2026.
- CVE Program. “CVE-2021-35587”. 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.