Denial of Service (DoS) Affecting github.com/hashicorp/vault/helper/proxyutil package, versions >=1.10.0 <1.17.2

Affected versions of this package are vulnerable to Denial of Service (DoS) due to the improper handling of requests from unauthorized IP addresses when the proxy_protocol_behavior is set to deny_unauthorized. An attacker can cause the server to shut down and stop responding to all HTTP requests by sending a request from an IP address not listed in proxy_protocol_authorized_addrs.

Note:

1. This is only exploitable if the proxy_protocol_behavior is configured to deny_unauthorized.

2. While this bug also affected versions of Vault up to 1.17.1 and 1.16.5, a separate regression in those release series did not allow Vault operators to configure the deny_unauthorized option, thus not allowing the conditions for the denial of service to occur.

Denial of Service (DoS) describes a family of attacks, all aimed at making a system inaccessible to its intended and legitimate users.

Unlike other vulnerabilities, DoS attacks usually do not aim at breaching security. Rather, they are focused on making websites and services unavailable to genuine users resulting in downtime.

One popular Denial of Service vulnerability is DDoS (a Distributed Denial of Service), an attack that attempts to clog network pipes to the system by generating a large volume of traffic from many machines.

When it comes to open source libraries, DoS vulnerabilities allow attackers to trigger such a crash or crippling of the service by using a flaw either in the application code or from the use of open source libraries.

Two common types of DoS vulnerabilities:

• High CPU/Memory Consumption- An attacker sending crafted requests that could cause the system to take a disproportionate amount of time to process. For example, commons-fileupload:commons-fileupload.

• Crash - An attacker sending crafted requests that could cause the system to crash. For Example, npm ws package

• GitHub Commit
• GitHub PR
• HashiCorp Discuss