SB2019112927 - Fedora 31 update for proftpd
Published: November 29, 2019 Updated: April 25, 2025
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 2 secuirty vulnerabilities.
1) NULL pointer dereference (CVE-ID: CVE-2019-19269)
The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to a NULL pointer dereference in tls_verify_crl() function in ProFTPD while processing data, returned by the OpenSSL sk_X509_REVOKED_value() function when encountering an empty CRL installed by a system administrator. A remote attacker can trigger the NULL pointer dereference error when validating the certificate of a client connecting to the server in a TLS client/server mutual-authentication setup.
Successful exploitation of the vulnerability will result in a denial of service condition.
2) Improper Certificate Validation (CVE-ID: CVE-2019-19270)
The vulnerability allows a remote non-authenticated attacker to manipulate data.
An issue was discovered in tls_verify_crl in ProFTPD through 1.3.6b. Failure to check for the appropriate field of a CRL entry (checking twice for subject, rather than once for subject and once for issuer) prevents some valid CRLs from being taken into account, and can allow clients whose certificates have been revoked to proceed with a connection to the server.
Remediation
Install update from vendor's website.