CVE-2019-10639 Information disclosure in n/a
Remote attackers can bypass KASLR by extracting kernel address offsets via IP ID collisions in UDP or ICMP traffic, facilitating further exploitation.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2019-10639?
CVE-2019-10639 is a high-severity vulnerability in Linux kernel, published on 5 Jul 2019. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
The Linux kernel 4.x (starting from 4.1) and 5.x before 5.0.8 allows Information Exposure (partial kernel address disclosure), leading to a KASLR bypass. Specifically, it is possible to extract the KASLR kernel image offset using the IP ID values the kernel produces for connection-less protocols (e.g., UDP and ICMP). When such traffic is sent to multiple destination IP addresses, it is possible to obtain hash collisions (of indices to the counter array) and thereby obtain the hashing key (via enumeration). This key contains enough bits from a kernel address (of a static variable) so when the key is extracted (via enumeration), the offset of the kernel image is exposed. This attack can be carried out remotely, by the attacker forcing the target device to send UDP or ICMP (or certain other) traffic to attacker-controlled IP addresses. Forcing a server to send UDP traffic is trivial if the server is a DNS server. ICMP traffic is trivial if the server answers ICMP Echo requests (ping). For client targets, if the target visits the attacker's web page, then WebRTC or gQUIC can be used to force UDP traffic to attacker-controlled IP addresses. NOTE: this attack against KASLR became viable in 4.1 because IP ID generation was changed to have a dependency on an address associated with a network namespace.
Weakness: CWE-326
Which versions are affected by CVE-2019-10639?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2019-10639?
Upgrade to a fixed version.
Is CVE-2019-10639 being exploited?
There is no known exploitation of CVE-2019-10639 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as DEBIAN-CVE-2019-10639, GHSA-r86q-xwfj-whpp, UBUNTU-CVE-2019-10639.