NULL pointer dereference in ProFTPD - CVE-2019-19269

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Main Vulnerability Database Vulnerabilities #VU26104

NULL pointer dereference in ProFTPD - CVE-2019-19269

Published: March 17, 2020 / Updated: September 7, 2020


Vulnerability identifier: #VU26104
CSH Severity: Medium
CVSS v4: 8.2 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2019-19269
CWE-ID: CWE-476
Exploitation vector: Remote access
Exploit availability: No public exploit available

Vulnerability details

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.


Affected software

ProFTPD
QNAP QTS
Gentoo Linux
Fedora
SUSE Linux
Opensuse
proftpd

How to mitigate CVE-2019-19269

Install updates from vendor's website.

ProFTPD - update to 1.3.6c
QNAP QTS - addressed in versions 4.2.6 20200821, 4.3.3.1386 20200821, 4.3.6.1411 20200825, 4.4.3.1400 20200817
proftpd - addressed in versions 1.3.3g-13.el6, 1.3.5e-8.el7, 1.3.6b-2.fc30, 1.3.6b-2.fc31

External References

Related Security Bulletins