8.5 HIGH
- CVSS version (CVSS): 3.1
- Attack Vector (AV): Network (N)
- Attack Complexity (AC): Low (L)
- Privileges Required (PR): Low (L)
- User Interaction (UI): None (N)
- Scope (S): Changed (C)
- Confidentiality (C): None (N)
- Integrity (I): High (H)
- Availability (A): Low (L)
- Modified Attack Vector (MAV): Network (N)
- Modified Attack Complexity (MAC): Low (L)
- Modified Privileges Required (MPR): Low (L)
- Modified User Interaction (MUI): None (N)
- Modified Confidentiality (MC): None (N)
- Modified Scope (MS): Changed (C)
- Modified Integrity (MI): High (H)
- Modified Availability (MA): Low (L)
Activity log
- Created suggestion
Fission: Incomplete capability denylist in Environment/Function PodSpec validation allows tenant-added CAP_SYS_TIME and cross-tenant node wall-clock corruption
Fission is an open-source, Kubernetes-native serverless framework that simplifies the deployment of functions and applications on Kubernetes. Prior to version 1.25.0, Fission added PodSpec safety validation for tenant-facing Environment and Function CRDs (ValidatePodSpecSafety / ValidateContainerSafety admission webhook + sanitizeContainerSecurityContext executor merge layer), but the capability check was implemented as a fixed denylist of six Linux capabilities (SYS_ADMIN, NET_ADMIN, SYS_PTRACE, SYS_MODULE, DAC_READ_SEARCH, DAC_OVERRIDE). The denylist omitted CAP_SYS_TIME, among others. As a result, a tenant who could create a Function or Environment CRD could request securityContext.capabilities.add: ["SYS_TIME"], pass Fission's admission validation and merge-layer sanitization, and run attacker-controlled code with CAP_SYS_TIME in the resulting function or runtime container. This issue has been patched in version 1.25.0.
References
-
https://github.com/fission/fission/security/advisories/GHSA-qf5v-m7p4-95rp x_refsource_CONFIRM
-
https://github.com/fission/fission/pull/3465 x_refsource_MISC
-
https://github.com/fission/fission/releases/tag/v1.25.0 x_refsource_MISC
Affected products
- ==< 1.25.0
Package maintainers
-
@NeverBehave Xinhao Luo <i@never.pet>