CVE-2022-25749 Transient Denial-of-Service in WLAN due to buffer over-read while parsing MDNS frames
Buffer over-read can occur when a device receives more data than it can store. In this case, the contents of the buffer might overwrite older data, causing corruption. The integrity of data received over the network can become compromised if the receiving device’s buffer is not large enough to hold all the data that is received. Depending on the size of the buffer, buffer overflow can result in data being lost. Buffer over-read can occur when a device receives more data than it can store. In this case, the contents of the buffer might overwrite older data, causing corruption. The integrity of data received over the network can become compromised if the receiving device’s buffer is not large enough to hold all the data that is received. Depending on the size of the buffer, buffer overflow can result in data being lost. When a device receives a packet that is too large for its buffer, the receiving device will buffer the data, then process it when its buffer is full. If the buffer is too small, the device will drop the packet. Buffer over-read can be exploited in a Denial-of-Service attack if the attacker sends a large amount of data to a vulnerable device.
Vulnerability overview:
Buffer overflow vulnerability is when a device receives more data than it can store. In this case, the contents of the buffer might overwrite older data, causing corruption. The integrity of data received over the network can become compromised if the receiving device’s buffer is not large enough to hold all the data that is received. Depending on the size of the buffer, buffer overflow can result in data being lost. When a device receives a packet that is too large for its buffer, the receiving device will buffer the data, then process it when its buffer is full. If the buffer is too small, the device will drop the packet. Buffer over-read can be exploited in a Denial-of-Service attack if the attacker sends a large amount of data to a vulnerable device.
Vulnerability Scenario
An attacker sent a large amount of data to a vulnerable device. When the buffer is full, the receiving device will drop the packet. Buffer over-read is exploitable in a Denial-of-Service attack if the attacker sends a large amount of data to a vulnerable device.
How Does Buffer Over-Read Work?
Buffer Over-read can occur when a device receives more data than it can store. In this case, the contents of the buffer might overwrite older data, causing corruption. The integrity of data received over the network can become compromised if the receiving device’s buffer is not large enough to hold all the data that is received. Depending on the size of the buffer, buffer overflow can result in data being lost.
How to trigger a Buffer Over-read
There are two methods of triggering a buffer over-read, both of which require the attacker to send data to the vulnerable device.
Method 1: Send a large amount of data, then close the connection with the vulnerable device
This method is typically used when an attacker wants to cause a Denial-of-Service attack. In this case, the attacker sends a large amount of data to the vulnerable device and then closes the connection with it, causing a buffer over-read.
Method 2: Send a small amount of data and keep sending it until you trigger an overflow
In this second method, the attacker sends a small amount of data to the vulnerable device and keeps sending it until they trigger an overflow. They can do that by continuously increasing the size of their packet or by sending packets with different sizes in it. This method works best when there is no way for other devices on the network to detect it because there is no burst of traffic from one specific device.
Timeline
Published on: 10/19/2022 11:15:00 UTC
Last modified on: 10/20/2022 21:06:00 UTC