An invalid pointer initialization issue was found in the SLiRP networking implementation of QEMU. The flaw exists in the udp6_input() function and could occur while processing a udp packet that is smaller than the size of the udphdr structure. This issue may lead to out-of-bounds read access or indirect host memory disclosure to the guest. The highest threat from this vulnerability is to data confidentiality. This flaw affects libslirp versions prior to 4.6.0.
The product accesses or uses a pointer that has not been initialized.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Libslirp | Libslirp_project | * | 4.6.0 (excluding) |
| Red Hat Enterprise Linux 8 | RedHat | virt-devel:rhel-8050020211001230723.b4937e53 | * |
| Red Hat Enterprise Linux 8 | RedHat | virt:rhel-8050020211001230723.b4937e53 | * |
| Libslirp | Ubuntu | devel | * |
| Libslirp | Ubuntu | focal | * |
| Libslirp | Ubuntu | groovy | * |
| Libslirp | Ubuntu | hirsute | * |
| Libslirp | Ubuntu | impish | * |
| Libslirp | Ubuntu | jammy | * |
| Libslirp | Ubuntu | kinetic | * |
| Libslirp | Ubuntu | lunar | * |
| Libslirp | Ubuntu | mantic | * |
| Libslirp | Ubuntu | noble | * |
| Libslirp | Ubuntu | oracular | * |
| Libslirp | Ubuntu | trusty | * |
| Libslirp | Ubuntu | xenial | * |
| Qemu | Ubuntu | bionic | * |
| Qemu | Ubuntu | esm-infra-legacy/trusty | * |
| Qemu | Ubuntu | esm-infra/xenial | * |
| Qemu | Ubuntu | trusty | * |
| Qemu | Ubuntu | trusty/esm | * |
| Qemu | Ubuntu | xenial | * |
If the pointer contains an uninitialized value, then the value might not point to a valid memory location. This could cause the product to read from or write to unexpected memory locations, leading to a denial of service. If the uninitialized pointer is used as a function call, then arbitrary functions could be invoked. If an attacker can influence the portion of uninitialized memory that is contained in the pointer, this weakness could be leveraged to execute code or perform other attacks. Depending on memory layout, associated memory management behaviors, and product operation, the attacker might be able to influence the contents of the uninitialized pointer, thus gaining more fine-grained control of the memory location to be accessed.