NGINX Multiple Module Vulnerabilities

Buffer overflow in NGINX's DAV module allows remote attackers to crash worker processes or manipulate file names outside the document root when MOVE/COPY methods are combined with prefix location and alias directives. The vulnerability affects NGINX Open Source and NGINX Plus installations using vulnerable configurations, though the low-privilege worker process context limits the scope of file manipulation. No patch is currently available for this high-severity issue.

NGINX worker process crashes via null pointer dereference in the mail authentication module when CRAM-MD5 or APOP authentication is configured with retry-enabled backend servers. This denial of service vulnerability affects NGINX Plus and NGINX Open Source with no patch currently available, allowing unauthenticated remote attackers to terminate worker processes and degrade service availability.

Integer overflow in NGINX 32-bit builds with the ngx_http_mp4_module allows local attackers to corrupt or overwrite worker process memory via specially crafted MP4 files, leading to denial of service. The vulnerability requires the mp4 directive to be enabled in the configuration and an attacker's ability to trigger MP4 file processing. No patch is currently available for affected deployments.

NGINX Open Source and NGINX Plus contain a buffer over-read or over-write vulnerability in the ngx_http_mp4_module that can lead to NGINX worker process termination or potentially remote code execution. An attacker with local access and the ability to supply a specially crafted MP4 file for processing can exploit this flaw when the mp4 directive is enabled in the configuration. The vulnerability has a CVSS score of 7.8 with high impact on confidentiality, integrity, and availability, though exploitation requires local access (AV:L) and low-level privileges (PR:L).

NGINX Plus and NGINX Open Source contain an improper handling vulnerability in the ngx_mail_smtp_module that allows DNS response injection through malformed CRLF sequences. An attacker controlling a DNS server can inject arbitrary headers into SMTP upstream requests, potentially manipulating mail routing and message content. With a CVSS score of 3.7 and low attack complexity, this represents an integrity issue rather than a critical exploitability threat, though it requires network-level DNS control.

NGINX Plus and NGINX Open Source contain an authentication bypass vulnerability in the ngx_stream_ssl_module where revoked certificates are incorrectly accepted during TLS handshakes despite OCSP checking. When ssl_verify_client and ssl_ocsp are both enabled, the module fails to properly enforce certificate revocation status, allowing clients with revoked certificates to establish connections. This affects both commercial NGINX Plus and open-source NGINX deployments with a CVSS score of 5.4 (Medium), representing a localized confidentiality and integrity impact requiring authenticated attackers.