SB2021060320 - Multiple vulnerabilities in Apache HTTP Server
Published: June 3, 2021
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 8 secuirty vulnerabilities.
1) NULL pointer dereference (CVE-ID: CVE-2021-31618)
The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to a NULL pointer dereference error in mod_http2 in Apache HTTP server. A remote attacker can send specially crafted request to the server and perform a denial of service (DoS) attack.
2) Input validation error (CVE-ID: CVE-2021-30641)
The vulnerability allows a remote attacker to bypass implemented security restrictions.
The vulnerability exists due to incorrect parsing of Apache configuration files. An unexpected
3) Stack-based buffer overflow (CVE-ID: CVE-2020-35452)
The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to a boundary error when processing Digest nounces in mod_auth_digest. A remote unauthenticated attacker can send a specially crafted HTTP request, trigger stack overflow by one nul byte and crash the server.
4) NULL pointer dereference (CVE-ID: CVE-2021-26691)
The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to a NULL pointer dereference error in mod_session. A a malicious backend server or SessionHeader can trigger a denial of service (DoS) condition.
5) NULL pointer dereference (CVE-ID: CVE-2021-26690)
The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to a NULL pointer dereference error in mod_session. A remote attacker can pass specially crafted data to the application and perform a denial of service (DoS) attack.
6) NULL pointer dereference (CVE-ID: CVE-2020-13950)
The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to a NULL pointer dereference error in mod_proxy_http. A remote attacker can pass specially crafted data to the application and perform a denial of service (DoS) attack.
7) Improper Privilege Management (CVE-ID: CVE-2020-13938)
The vulnerability allows a local user to stop the service.
The vulnerability exists due to improper privilege management. A local user can on the Windows system can stop the Apache HTTP server service.
8) Security restrictions bypass (CVE-ID: CVE-2019-17567)
The vulnerability allows a remote attacker to bypass implemented security restrictions.
The vulnerability exists due to unspecified error within the mod_proxy_wstunnel and mod_proxy_http modules. If mod_proxy_wstunnel is configured on an URL that is not necessarily Upgraded by the origin server and is tunneling the whole connection regardless, thus allowing for subsequent requests on the same connection to pass through with no HTTP validation, authentication or authorization possibly configured.
Remediation
Install update from vendor's website.