melange allows users to build apk packages using declarative pipelines. Apko prior to version 1.2.9, corresponding to melange prior to version 0.50.4, verified the control section hash (`.PKGINFO` etc.) against the signed `APKINDEX`, but never verified the data section hash (the actual package files that get installed). An attacker who could compromise a mirror, poison a cache, or MITM a package fetch could substitute arbitrary file contents while the control hash check still passed.
Apko version 1.2.9 and melange version 0.50.4 contain a fix.
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
High
Difficult to exploit
Privileges Required
None
No privileges needed
User Interaction
Required
User action required
Impact Assessment
Confidentiality
High
Complete data leak
Integrity
High
Complete data modification
Availability
High
Complete denial of service
CVSS Vector v3.1