In YARA 3.8.1, bytecode in a specially crafted compiled rule can read uninitialized data from VM scratch memory in libyara/exec.c. This can allow attackers to discover addresses in the real stack (not the YARA virtual stack).
Weakness
The product uses or accesses a resource that has not been initialized.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Yara | Virustotal | 3.8.1 (including) | 3.8.1 (including) |
| Yara | Ubuntu | bionic | * |
| Yara | Ubuntu | cosmic | * |
| Yara | Ubuntu | eoan | * |
| Yara | Ubuntu | groovy | * |
| Yara | Ubuntu | hirsute | * |
| Yara | Ubuntu | impish | * |
| Yara | Ubuntu | kinetic | * |
| Yara | Ubuntu | lunar | * |
| Yara | Ubuntu | mantic | * |
| Yara | Ubuntu | plucky | * |
| Yara | Ubuntu | trusty | * |
| Yara | Ubuntu | xenial | * |
Potential Mitigations
References
- https://bnbdr.github.io/posts/extracheese/
- https://github.com/VirusTotal/yara/issues/999
- https://github.com/bnbdr/swisscheese/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/DFFXDAMP6GJ337LIOTVF5I4T6QGMN3ZR/
- https://bnbdr.github.io/posts/extracheese/
- https://github.com/VirusTotal/yara/issues/999
- https://github.com/bnbdr/swisscheese/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/DFFXDAMP6GJ337LIOTVF5I4T6QGMN3ZR/