SB2019090202 - Ubuntu update for Apache HTTP Server
Published: September 2, 2019
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 7 secuirty vulnerabilities.
1) Resource management error (CVE-ID: CVE-2019-0197)
The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to an error within the mod_http2 module when processing update requests from http/1.1 to http/2, if this was not the first request on a connection. A remote attacker can send specially crafted requests to the affected server and perform denial of service attack.
Successful exploitation of the vulnerability requires that HTTP/2 protocol is enabled for a "http:" host or H2Upgrade is enabled for h2 on a "https:" host.
2) Out-of-bounds write (CVE-ID: CVE-2019-10081)
The vulnerability allows a remote attacker to perform denial of service attack.
The vulnerability exists due to a boundary error when processing HTTP/2 requests within the mod_http2 module, configured with "H2PushResource". A remote attacker can send specially crafted HTTP/2 requests to the affected server and perform denial of service (DoS) attack.
3) Use-after-free (CVE-ID: CVE-2019-10082)
The vulnerability allows a remote attacker to perform denial of service (DoS) attack.
The vulnerability exists due to a use-after-free error within the mod_http2 when handling connection shutdown. A remote attacker can send specially crafted requests to the affected server and make the mod_http2 to read memory that was already freed.
4) Cross-site scripting (CVE-ID: CVE-2019-10092)
The disclosed vulnerability allows a remote attacker to perform cross-site scripting (XSS) attacks.
The vulnerability exists due to insufficient sanitization of user-supplied data on the mod_proxy error page. A remote attacker can trick the victim to follow a specially crafted link and execute arbitrary HTML and script code in user's browser in context of vulnerable website.
Successful exploitation of this vulnerability may allow a remote attacker to steal potentially sensitive information, change appearance of the web page, perform phishing and drive-by-download attacks.
5) NULL pointer dereference (CVE-ID: CVE-2019-10097)
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 PROXY header within the mod_remoteip. A remote attacker that controls a trusted proxy server can send a specially crafted PROXY header, trigger stack overflow and perform a denial of service (DoS) attack.
6) Input validation error (CVE-ID: CVE-2019-10098)
The vulnerability allows a remote attacker to bypass certain security restrictions.
The vulnerability exists due to incorrect handling of encoded line break characters within rewrite rules. A remote attacker can send a specially crafted HTTP request and potentially bypass security restrictions.
7) Resource management error (CVE-ID: CVE-2019-9517)
The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to incorrect implementation of HTTP/2 protocol. A remote attacker can open the HTTP/2 window so the peer can send without constraint; however, they leave the TCP window closed so the peer cannot actually write (many of) the bytes on the wire. The attacker then sends a stream of requests for a large response object. Depending on how the servers queue the responses, this can consume excess memory, CPU, or both.Remediation
Install update from vendor's website.