OpenSSL Denial-of-Service Vulnerability (CVE-2020-1971) Threat Alert

OpenSSL Denial-of-Service Vulnerability (CVE-2020-1971) Threat Alert

janeiro 5, 2021 | Adeline Zhang


On December 8, 2020, local time, OpenSSL released a security advisory disclosing a NULL pointer dereference vulnerability (CVE-2020-1971), rating the vulnerability as High-risk.

The vulnerability exists in the GENERAL_NAME_cmp function in OpenSSL. GENERAL_NAME_cmp compares different instances of a GENERAL_NAME to see if they are equal or not. When both GENERAL_NAMEs contain EDIPartyName, a NULL pointer dereference and a crash may occur, eventually causing a denial of service.

Therefore, if an attacker can control both items being compared, a crash might be triggered. For example, the attacker can trick a client or server into checking a malicious certificate against a malicious CRL.

Reference link:

Affected Versions

  • OpenSSL 1.1.1
  • OpenSSL 1.0.2 (out of support)

Unaffected Version

  • OpenSSL 1.1.1i


OpenSSL has released new versions to fix the vulnerability. Affected users are advised to upgrade without delay.

The update is available at the following link:


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