On arm64, a WASM br_table instruction with a lot of entries could lead to the label being too far from the instruction causing truncation and incorrect computation of the branch address. This vulnerability affects Firefox < 141, Firefox ESR < 115.26, Firefox ESR < 128.13, Firefox ESR < 140.1, Thunderbird < 141, Thunderbird < 128.13, and Thunderbird < 140.1.
The device is missing or incorrectly implements circuitry or sensors that detect and mitigate the skipping of security-critical CPU instructions when they occur.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Mozjs102 | Ubuntu | esm-apps/noble | * |
| Mozjs102 | Ubuntu | jammy | * |
| Mozjs102 | Ubuntu | noble | * |
| Mozjs115 | Ubuntu | devel | * |
| Mozjs115 | Ubuntu | noble | * |
| Mozjs115 | Ubuntu | plucky | * |
| Mozjs52 | Ubuntu | esm-apps/focal | * |
| Mozjs52 | Ubuntu | esm-infra/bionic | * |
| Mozjs68 | Ubuntu | esm-infra/focal | * |
| Mozjs78 | Ubuntu | esm-apps/jammy | * |
| Mozjs78 | Ubuntu | jammy | * |
| Mozjs91 | Ubuntu | jammy | * |
| Thunderbird | Ubuntu | jammy | * |
| Thunderbird | Ubuntu | upstream | * |
The operating conditions of hardware may change in ways that cause unexpected behavior to occur, including the skipping of security-critical CPU instructions. Generally, this can occur due to electrical disturbances or when the device operates outside of its expected conditions. In practice, application code may contain conditional branches that are security-sensitive (e.g., accepting or rejecting a user-provided password). These conditional branches are typically implemented by a single conditional branch instruction in the program binary which, if skipped, may lead to effectively flipping the branch condition - i.e., causing the wrong security-sensitive branch to be taken. This affects processes such as firmware authentication, password verification, and other security-sensitive decision points. Attackers can use fault injection techniques to alter the operating conditions of hardware so that security-critical instructions are skipped more frequently or more reliably than they would in a “natural” setting.