An issue was discovered in Pillow before 8.1.1. The PDF parser allows a regular expression DoS (ReDoS) attack via a crafted PDF file because of a catastrophic backtracking regex.
Weakness
The product uses a regular expression with an inefficient, possibly exponential worst-case computational complexity that consumes excessive CPU cycles.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Pillow | Python | * | 8.1.1 (excluding) |
| Red Hat Enterprise Linux 8 | RedHat | python-pillow-0:5.1.1-16.el8 | * |
| Red Hat Quay 3 | RedHat | quay/quay-rhel8:v3.6.0-62 | * |
| Pillow | Ubuntu | bionic | * |
| Pillow | Ubuntu | esm-infra/bionic | * |
| Pillow | Ubuntu | esm-infra/focal | * |
| Pillow | Ubuntu | focal | * |
| Pillow | Ubuntu | groovy | * |
| Pillow | Ubuntu | trusty | * |
| Pillow | Ubuntu | upstream | * |
| Pillow-python2 | Ubuntu | focal | * |
| Pillow-python2 | Ubuntu | groovy | * |
| Python-imaging | Ubuntu | precise/esm | * |
Extended Description
Attackers can create crafted inputs that
intentionally cause the regular expression to use
excessive backtracking in a way that causes the CPU
consumption to spike.