CVE-2021-3711

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.
• AutomatableyesAn attacker can reliably automate reconnaissance through exploitation, so this scales.
• Technical ImpacttotalSuccessful exploitation gives total 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

87.81% probability of exploitation activity in the next 30 days.

EPSS percentile

Equal to or higher than the score of 99.7% of scored records. A rank, not a probability.

NVD base score

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

NVD CVSS vector

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

NVD analysis status

Modified. NVD last modified this record on 2026-10-08.

Red Hat severity

Important. 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

2021-08-24 14:50Z5 YR AGO

Last updated

2026-10-08 21:03Z20 DAYS AGO

Reserved

2021-08-16

Assigning CNA

openssl

Record state

PUBLISHED

Severity

Not rated by the issuing CNA

CNA CVSS vector

Not published by the issuing CNA

Weaknesses

• CWE-120Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')Base

Data version

5.2

Document digest

8ea87114c7e5de4768cf75b5d18cf7157a0167750d6276942106d4ef0c0b1e61

• www.openssl.orghttps://www.openssl.org/news/secadv/20210824.txt
• git.openssl.orghttps://git.openssl.org/gitweb/?p=openssl.git%3Ba=commitdiff%3Bh=59f5e75f3bced8fc0e130d72a3f582cf7b480b46
• www.debian.orgDSA-4963https://www.debian.org/security/2021/dsa-4963vendor-advisory
• lists.apache.org[tomcat-dev] 20210825 OpenSSL security announcement - do we need a Tomcat Native release?https://lists.apache.org/thread.html/r18995de860f0e63635f3008fd2a6aca82394249476d21691e7c59c9e%40%3Cdev.tomcat.apache.org%3Emailing-list
• www.openwall.com[oss-security] 20210825 OpenSSL SM2 Decryption Buffer Overflow (CVE-2021-3711), Read buffer overruns processing ASN.1 strings (CVE-2021-3712)http://www.openwall.com/lists/oss-security/2021/08/26/2mailing-list
• lists.apache.org[tomcat-dev] 20210826 Re: OpenSSL security announcement - do we need a Tomcat Native release?https://lists.apache.org/thread.html/rad5d9f83f0d11fb3f8bb148d179b8a9ad7c6a17f18d70e5805a713d1%40%3Cdev.tomcat.apache.org%3Emailing-list
• security.netapp.comhttps://security.netapp.com/advisory/ntap-20210827-0010/
• www.oracle.comhttps://www.oracle.com/security-alerts/cpuoct2021.html
• www.tenable.comhttps://www.tenable.com/security/tns-2021-16
• www.oracle.comhttps://www.oracle.com/security-alerts/cpujan2022.html
• security.netapp.comhttps://security.netapp.com/advisory/ntap-20211022-0003/
• www.tenable.comhttps://www.tenable.com/security/tns-2022-02
• www.oracle.comhttps://www.oracle.com/security-alerts/cpuapr2022.html
• cert-portal.siemens.comhttps://cert-portal.siemens.com/productcert/pdf/ssa-389290.pdf
• security.gentoo.orgGLSA-202209-02https://security.gentoo.org/glsa/202209-02vendor-advisory
• security.gentoo.orgGLSA-202210-02https://security.gentoo.org/glsa/202210-02vendor-advisory
• security.netapp.comhttps://security.netapp.com/advisory/ntap-20240621-0006/