CVE-2021-23841

Exploitation

Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.

SSVC decision

• ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
• AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
• Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.

CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.

EPSS probability

7.41% probability of exploitation activity in the next 30 days.

EPSS percentile

Ranks above 94.0% of scored records. A rank, not a probability.

NVD base score

5.9 (CVSS v3.x), scored by the NVD independently of the CNA.

NVD CVSS vector

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

NVD analysis status

Modified. NVD last modified this record on 2026-06-17.

Red Hat severity

Moderate. Red Hat's rating for its own products, not a CVSS rating.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

Published

2021-02-16 16:55Z5 YR AGO

Last updated

2024-09-16 22:39Z1 YR AGO

Reserved

2021-01-12

Assigning CNA

openssl

Record state

PUBLISHED

Severity

Not rated by the issuing CNA

CNA CVSS vector

Not published by the issuing CNA

Weaknesses

• CWE-476NULL Pointer DereferenceBase

Data version

5.1

Document digest

c20c8ed86c2a71d915e37f6b458e3e0ad36b073070ef334a60a7d5c5e4208879

• www.openssl.orghttps://www.openssl.org/news/secadv/20210216.txt
• git.openssl.orghttps://git.openssl.org/gitweb/?p=openssl.git%3Ba=commitdiff%3Bh=122a19ab48091c657f7cb1fb3af9fc07bd557bbf
• git.openssl.orghttps://git.openssl.org/gitweb/?p=openssl.git%3Ba=commitdiff%3Bh=8252ee4d90f3f2004d3d0aeeed003ad49c9a7807
• www.debian.orgDSA-4855https://www.debian.org/security/2021/dsa-4855vendor-advisory
• security.gentoo.orgGLSA-202103-03https://security.gentoo.org/glsa/202103-03vendor-advisory
• seclists.org20210526 APPLE-SA-2021-05-25-2 macOS Big Sur 11.4http://seclists.org/fulldisclosure/2021/May/70mailing-list
• seclists.org20210526 APPLE-SA-2021-05-25-5 Safari 14.1.1http://seclists.org/fulldisclosure/2021/May/68mailing-list
• seclists.org20210526 APPLE-SA-2021-05-25-1 iOS 14.6 and iPadOS 14.6http://seclists.org/fulldisclosure/2021/May/67mailing-list
• www.oracle.comhttps://www.oracle.com/security-alerts/cpuApr2021.html
• www.tenable.comhttps://www.tenable.com/security/tns-2021-09
• security.netapp.comhttps://security.netapp.com/advisory/ntap-20210513-0002/
• security.netapp.comhttps://security.netapp.com/advisory/ntap-20210219-0009/
• www.tenable.comhttps://www.tenable.com/security/tns-2021-03
• support.apple.comhttps://support.apple.com/kb/HT212529
• support.apple.comhttps://support.apple.com/kb/HT212528
• support.apple.comhttps://support.apple.com/kb/HT212534
• www.oracle.comhttps://www.oracle.com//security-alerts/cpujul2021.html
• kb.pulsesecure.nethttps://kb.pulsesecure.net/articles/Pulse_Security_Advisories/SA44846
• www.oracle.comhttps://www.oracle.com/security-alerts/cpuoct2021.html
• www.oracle.comhttps://www.oracle.com/security-alerts/cpuapr2022.html
• cert-portal.siemens.comhttps://cert-portal.siemens.com/productcert/pdf/ssa-637483.pdf
• security.netapp.comhttps://security.netapp.com/advisory/ntap-20240621-0006/