SB2021032938 - Fedora 34 update for openssl
Published: March 29, 2021
Security Bulletin ID
SB2021032938
Severity
Medium
Patch available
YES
Number of vulnerabilities
2
Exploitation vector
Remote access
Highest impact
Denial of service
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 2 secuirty vulnerabilities.
1) NULL pointer dereference (CVE-ID: CVE-2021-3449)
The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to a NULL pointer dereference error when processing TLSv1.2 renegotiations. A remote attacker can send a maliciously crafted renegotiation ClientHello message, which omits the signature_algorithms extension but includes a signature_algorithms_cert extension, trigger a NULL pointer dereference error and crash the server.2) Security features bypass (CVE-ID: CVE-2021-3450)
The vulnerability allows a remote attacker to bypass implemented security restrictions.
The vulnerability exists due to an error in implementation of the X509_V_FLAG_X509_STRICT flag allows an attacker to overwrite a valid CA certificate using any non-CA certificate in the chain. As a result, a remote attacker can perform MitM attack.
Remediation
Install update from vendor's website.