Bubblewrap (bwrap) before version 0.4.1, if installed in setuid mode and the kernel supports unprivileged user namespaces, then the bwrap --userns2 option can be used to make the setuid process keep running as root while being traceable. This can in turn be used to gain root permissions. Note that this only affects the combination of bubblewrap in setuid mode (which is typically used when unprivileged user namespaces are not supported) and the support of unprivileged user namespaces. Known to be affected are: * Debian testing/unstable, if unprivileged user namespaces enabled (not default) * Debian buster-backports, if unprivileged user namespaces enabled (not default) * Arch if using linux-hardened, if unprivileged user namespaces enabled (not default) * Centos 7 flatpak COPR, if unprivileged user namespaces enabled (not default) This has been fixed in the 0.4.1 release, and all affected users should update.
The product does not conform to the API requirements for a function call that requires extra privileges. This could allow attackers to gain privileges by causing the function to be called incorrectly.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Bubblewrap | Projectatomic | * | 0.4.1 (excluding) |
| Bubblewrap | Ubuntu | devel | * |
| Bubblewrap | Ubuntu | focal | * |
| Bubblewrap | Ubuntu | groovy | * |
| Bubblewrap | Ubuntu | trusty | * |
| Bubblewrap | Ubuntu | upstream | * |
When a product contains certain functions that perform operations requiring an elevated level of privilege, the caller of a privileged API must be careful to:
If the caller of the API does not follow these requirements, then it may allow a malicious user or process to elevate their privilege, hijack the process, or steal sensitive data. For instance, it is important to know if privileged APIs do not shed their privileges before returning to the caller or if the privileged function might make certain assumptions about the data, context or state information passed to it by the caller. It is important to always know when and how privileged APIs can be called in order to ensure that their elevated level of privilege cannot be exploited.