`CVE-2021-23841` OpenSSL

Affected software	OpenSSL
Severity	5.9 Medium CVSS 3.1 2 scores
Weakness	CWE-476
Published	16 Feb 2021
Updated	17 Jun 2026

Description

The OpenSSL public API function X509_issuer_and_serial_hash() attempts to create a unique hash value based on the issuer and serial number data contained within an X509 certificate. However it fails to correctly handle any errors that may occur while parsing the issuer field (which might occur if the issuer field is maliciously constructed). This may subsequently result in a NULL pointer deref and a crash leading to a potential denial of service attack. The function X509_issuer_and_serial_hash() is never directly called by OpenSSL itself so applications are only vulnerable if they use this function directly and they use it on certificates that may have been obtained from untrusted sources. OpenSSL versions 1.1.1i and below are affected by this issue. Users of these versions should upgrade to OpenSSL 1.1.1j. OpenSSL versions 1.0.2x and below are affected by this issue. However OpenSSL 1.0.2 is out of support and no longer receiving public updates. Premium support customers of OpenSSL 1.0.2 should upgrade to 1.0.2y. Other users should upgrade to 1.1.1j. Fixed in OpenSSL 1.1.1j (Affected 1.1.1-1.1.1i). Fixed in OpenSSL 1.0.2y (Affected 1.0.2-1.0.2x).

Exploitation status

No public exploit

No exploit has been reported in the sources we check. Published 5 years ago.

CISA KEV not listed
VulnCheck KEV not listed
CISA Vulnrichment exploitation: none
Indexed PoC none indexed
EPSS 7.5% chance in 30 days

Waratek protection

Outside Waratek scope

A Java vulnerability, but not one Waratek protects. It affects only Java on a user's desktop (applets, Web Start, JavaFX, the installer), sits in a product the Waratek agent can't be installed into, or is in a package we don't expect in business applications. The decision below says which.

Protection none
Action not pursued none
Review human Researcher
Record active

Decided by	Manual classification of this CVE in the legacy dataset
Finding	A manual classification set this CVE's status to Outside Waratek scope, but the CVE names a tracked product.

Decided by

Manual classification of this CVE in the legacy dataset

Finding

A manual classification set this CVE's status to Outside Waratek scope, but the CVE names a tracked product.

CVSS

5.9 MEDIUM v3.1 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H 2 metrics

We show the highest score from the newest CVSS version. Scores from different versions can't be compared, and the first score listed is sometimes a 0.0 placeholder.

Version Score Band Vector Assigner Type

CVSS 3.1 5.9 MEDIUM CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H NVD Primary published

CVSS 2.0 4.3 none AV:N/AC:M/Au:N/C:N/I:N/A:P NVD Primary

Version	Score	Band	Vector	Assigner	Type
CVSS 3.1	5.9	MEDIUM	`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H`	NVD	Primary	published
CVSS 2.0	4.3	none	`AV:N/AC:M/Au:N/C:N/I:N/A:P`	NVD	Primary

Affected software and releases

Oracle advisories

Advisory	Type	Quarter	Products Oracle names in its risk matrix
Oracle Critical Patch Update October 2021 ↗	CPU	2021-Q4	Oracle Fusion Middleware / Analytics Server (OpenSSL) (5.5.0.0.0, 5.9.0.0.0, 12.2.1.3.0, 12.2.1.4.0)
Oracle Critical Patch Update April 2021 ↗	CPU	2021-Q2	Oracle Java SE / Node (OpenSSL) (Oracle GraalVM Enterprise Edition: 19.3.5, 20.3.1.2, 21.0.0.2) Oracle MySQL / Monitoring: General (OpenSSL) (8.0.23 and prior) Oracle MySQL / Server: Security: Encryption (OpenSSL) (5.7.33 and prior, 8.0.23 and prior)

Advisory

Type

Quarter

Products Oracle names in its risk matrix

Oracle Critical Patch Update October 2021 ↗

CPU

2021-Q4

Oracle Fusion Middleware / Analytics Server (OpenSSL) (5.5.0.0.0, 5.9.0.0.0, 12.2.1.3.0, 12.2.1.4.0)

Oracle Critical Patch Update April 2021 ↗

CPU

2021-Q2

Oracle Java SE / Node (OpenSSL) (Oracle GraalVM Enterprise Edition: 19.3.5, 20.3.1.2, 21.0.0.2)
Oracle MySQL / Monitoring: General (OpenSSL) (8.0.23 and prior)
Oracle MySQL / Server: Security: Encryption (OpenSSL) (5.7.33 and prior, 8.0.23 and prior)

Oracle components and versions

Family	Component	Versions, as Oracle lists them	Read as
Oracle Fusion Middleware	Analytics Server (OpenSSL)	5.5.0.0.0, 5.9.0.0.0, 12.2.1.3.0, 12.2.1.4.0	5.5.0.0.0 · 5.9.0.0.0 · 12.2.1.3.0 · 12.2.1.4.0
Oracle Java SE	Node (OpenSSL)	Oracle GraalVM Enterprise Edition: 19.3.5, 20.3.1.2, 21.0.0.2	19.3.5.0 · 20.3.1.0 · 21.0.0.0
Oracle MySQL	Monitoring: General (OpenSSL)	8.0.23 and prior
Oracle MySQL	Server: Security: Encryption (OpenSSL)	5.7.33 and prior, 8.0.23 and prior

Family

Component

Versions, as Oracle lists them

Read as

Oracle Fusion Middleware

Analytics Server (OpenSSL)

5.5.0.0.0, 5.9.0.0.0, 12.2.1.3.0, 12.2.1.4.0

5.5.0.0.0 · 5.9.0.0.0 · 12.2.1.3.0 · 12.2.1.4.0

Oracle Java SE

Node (OpenSSL)

Oracle GraalVM Enterprise Edition: 19.3.5, 20.3.1.2, 21.0.0.2

19.3.5.0 · 20.3.1.0 · 21.0.0.0

Oracle MySQL

Monitoring: General (OpenSSL)

8.0.23 and prior

Oracle MySQL

Server: Security: Encryption (OpenSSL)

5.7.33 and prior, 8.0.23 and prior

Products and versions

23 products, 38 version entries

Source	Vendor	Product	Scheme	Affected versions
nvd	apple	ipados	generic	＜ 14.6
nvd	apple	iphone os	generic	＜ 14.6
nvd	apple	macos	generic	≥ 11.1 and ＜ 11.4
nvd	apple	safari	generic	＜ 14.1.1
nvd	debian	debian linux	generic	10.0
nvd	netapp	oncommand insight	generic	any version
nvd	netapp	oncommand workflow automation	generic	any version
nvd	netapp	snapcenter	generic	any version
nvd	openssl	openssl	generic	≥ 1.0.2 and ＜ 1.0.2 · ≥ 1.1.1 and ＜ 1.1.1
nvd	oracle	business intelligence	generic	5.5.0.0.0 · 5.9.0.0.0 · 12.2.1.3.0 · 12.2.1.4.0
nvd	oracle	communications cloud native core policy	generic	1.15.0
nvd	oracle	enterprise manager for storage management	generic	13.4.0.0
nvd	oracle	enterprise manager ops center	generic	12.4.0.0
nvd	oracle	essbase	generic	21.2
nvd	oracle	graalvm	javase	19.3.5 · 20.3.1.2 · 21.0.0.2
nvd	oracle	jd edwards world security	generic	a9.4
nvd	oracle	mysql enterprise monitor	generic	＜ 8.0.23
nvd	oracle	mysql server	generic	＜ 5.7.33 · ≥ 8.0.15 and ＜ 8.0.23
nvd	oracle	peoplesoft enterprise peopletools	generic	8.57 · 8.58 · 8.59
nvd	oracle	zfs storage appliance kit	generic	8.8
nvd	siemens	sinec ins	generic	1.0 · ＜ 1.0 · 1.0:sp1
nvd	tenable	nessus network monitor	generic	5.11.0 · 5.11.1 · 5.12.0 · 5.12.1 · 5.13.0
nvd	tenable	tenable.sc	generic	≥ 5.13.0 and ≤ 5.17.0

Source

Vendor

Product

Scheme

Affected versions

nvd

apple

ipados

generic

＜ 14.6

nvd

apple

iphone os

generic

＜ 14.6

nvd

apple

macos

generic

≥ 11.1 and ＜ 11.4

nvd

apple

safari

generic

＜ 14.1.1

nvd

debian

debian linux

generic

10.0

nvd

netapp

oncommand insight

generic

any version

nvd

netapp

oncommand workflow automation

generic

any version

nvd

netapp

snapcenter

generic

any version

nvd

openssl

generic

≥ 1.0.2 and ＜ 1.0.2 · ≥ 1.1.1 and ＜ 1.1.1

nvd

oracle

business intelligence

generic

5.5.0.0.0 · 5.9.0.0.0 · 12.2.1.3.0 · 12.2.1.4.0

nvd

oracle

communications cloud native core policy

generic

1.15.0

nvd

oracle

enterprise manager for storage management

generic

13.4.0.0

nvd

oracle

enterprise manager ops center

generic

12.4.0.0

nvd

oracle

essbase

generic

21.2

nvd

oracle

graalvm

javase

19.3.5 · 20.3.1.2 · 21.0.0.2

nvd

oracle

jd edwards world security

generic

a9.4

nvd

oracle

mysql enterprise monitor

generic

＜ 8.0.23

nvd

oracle

mysql server

generic

＜ 5.7.33 · ≥ 8.0.15 and ＜ 8.0.23

nvd

oracle

peoplesoft enterprise peopletools

generic

8.57 · 8.58 · 8.59

nvd

oracle

zfs storage appliance kit

generic

8.8

nvd

siemens

sinec ins

generic

1.0 · ＜ 1.0 · 1.0:sp1

nvd

tenable

nessus network monitor

generic

5.11.0 · 5.11.1 · 5.12.0 · 5.12.1 · 5.13.0

nvd

tenable

tenable.sc

generic

≥ 5.13.0 and ≤ 5.17.0

Earlier manual review

A reviewer classified this CVE in an older dataset. We kept the labels and products below, but not the reviewer's reasoning.

## Manual Classification Context **Labels:** NODE (OPENSSL), MYSQL PROTOCOL, SERVER: SECURITY: ENCRYPTION (OPENSSL), HTTPS, MONITORING: GENERAL (OPENSSL), NO AUTH REMOTE EXPLOIT, ANALYTICS SERVER (OPENSSL) **Products:** ORACLE GRAALVM ENTERPRISE EDITION, MYSQL SERVER, OPENSSL, ORACLE JAVA SE, MYSQL ENTERPRISE MONITOR, ORACLE MYSQL, ORACLE FUSION MIDDLEWARE, ORACLE BUSINESS INTELLIGENCE ENTERPRISE EDITION

References

URL	Tags
http://seclists.org/fulldisclosure/2021/May/67	Mailing List, Third Party Advisory
http://seclists.org/fulldisclosure/2021/May/68	Mailing List, Third Party Advisory
http://seclists.org/fulldisclosure/2021/May/70	Mailing List, Third Party Advisory
https://cert-portal.siemens.com/productcert/pdf/ssa-637483.pdf	Patch, Third Party Advisory
https://git.openssl.org/gitweb/?p=openssl.git%3Ba=commitdiff%3Bh=122a19ab48091c657f7cb1fb3af9fc07bd557bbf
https://git.openssl.org/gitweb/?p=openssl.git%3Ba=commitdiff%3Bh=8252ee4d90f3f2004d3d0aeeed003ad49c9a7807
https://kb.pulsesecure.net/articles/Pulse_Security_Advisories/SA44846	Third Party Advisory
https://security.gentoo.org/glsa/202103-03	Third Party Advisory
https://security.netapp.com/advisory/ntap-20210219-0009/	Third Party Advisory
https://security.netapp.com/advisory/ntap-20210513-0002/	Third Party Advisory

URL

Timeline

Published	2021-02-16	By the CVE Program.
NVD record modified	2026-06-17	NVD's own last-modified date for this record.

Published

2021-02-16

By the CVE Program.

NVD record modified

2026-06-17

NVD's own last-modified date for this record.

How VRT decided (5 of 24 rules ran)

5 of 24 rules ran. The rest didn't run because an earlier rule had already settled the CVE.

# Rule Outcome Status Detail

identity: Does this identifier describe a vulnerability at all? the first rule that matches decides

1 rejected no match CVE Program withdrawal of this identifier

scope: Is it a vulnerability Waratek protects? the first rule that matches decides

2 armr-patch-file no match An ARMR patch file on disk for this CVE

3 armr-secure-rule-file no match An ARMR security-rule template on disk for this CVE

4 manual-classification no match A researcher's recorded decision for this specific CVE

5 manual classification decided it matched Outside Waratek scope Found in legacy manual classifications

6 non-java-upstream not reached A root cause in non-Java code: an OS kernel, a C library, or a bundled runtime

7 oracle-component not reached The defect being in a component of a tracked product the agent does not reach: JavaFX, the Java SE installer, the JInitiator browser plug-in, the native WebLogic proxy plug-in, or a native part of Oracle Application Server or Collaboration Suite (HTTP Server, Web Cache, Internet Directory, mail and calendar servers). Oracle gives these no CPE of their own and names them only in the description.

8 java-client-side not reached Oracle's own risk-matrix note saying the CVE is reached only through untrusted code in the Java sandbox (applets, Web Start) or only through a client installation of Java, so a server running its own trusted code is not exposed

9 osv-maven not reached An OSV.dev record of this CVE affecting a package published to Maven Central. When every such package is one business applications do not use (Minecraft mods and launchers, Fastjson) and no tracked product is named by CPE, it settles the CVE as Outside Waratek scope instead

10 cna-maven-package not reached An affected Maven artifact named by the CNA itself

11 known-cpe-product not reached An NVD CPE naming a product ARMR tracks

12 cna-cpe-product not reached A CPE the CNA published naming a tracked product. Oracle publishes these on advisory day, months before NVD.

13 oracle-advisory-family not reached A tracked product family named in Oracle's own risk matrix. CPE cannot carry a suite name, only a module.

14 cna-named-product not reached A tracked product named in words by the CVE's own CNA, on a record with no CPE yet. Apache and Eclipse publish these on advisory day, before NVD adds CPE data.

15 non-deployable-product not reached The only affected product being a sealed appliance image, where Java runs but no -javaagent can be attached

16 unmatched-product not reached No tracked product matched above, and none present at all

disposition: What do we do about one that is? every rule runs

17 patch-hint not reached A reference pointing at the upstream fix: a commit, a PR, a Red Hat bug

18 open-source-maven not reached The affected package being open source on Maven, so the fix can be read

19 poc-derivable not reached An indexed exploit clearing the evidence bar to reverse-engineer, where there is no source to read

20 no-exploit not reached Nothing to build a rule from yet: no published exploit, no CISA record of exploitation and no source-level change to read

21 secure-rule-match not reached A vulnerability class already blocked by an ARMR security rule

22 exploited-no-fix-or-poc not reached Somebody exploiting this CVE (a CISA or VulnCheck KEV listing, or a CISA verdict of active exploitation), with no fix, source code or PoC to build a rule from

23 below-action-threshold not reached Medium or Low severity, no CISA or VulnCheck KEV listing, no PoC clearing the evidence bar, no CISA verdict, no Oracle advisory

24 no-exploit-published not reached Exploit code for this candidate, published in a reviewed catalogue or a GitHub repository with 5 or more stars, or in use per CISA or VulnCheck; not only a CISA verdict, a forecast, or nothing at all

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