pybars4 through 0.9.13 contains a code injection vulnerability in pybars/_compiler.py that allows attackers to execute Python code via unescaped bracketed path segments in Handlebars templates. Attackers can supply a template with a crafted segment in a helper or block argument to break out of the generated resolve() string literal and execute code in the application process.
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
High
Difficult to exploit
Attack Requirements
Present
Additional conditions required
Privileges Required
None
No privileges needed
User Interaction
None
No user interaction needed
Impact Assessment
Confidentiality
High
Complete data leak
Integrity
High
Complete data modification
Availability
High
Complete denial of service
CVSS Vector v4.0
Weakness Type (CWE)
References 4
https://github.com/up9inc/pybars4
disclosure@vulncheck.com
https://github.com/up9inc/pybars4/blob/0.9.13/pybars/_compiler.py#L153-L154
disclosure@vulncheck.com
https://github.com/vladko312/advisories/blob/702e98db9642ece70d9e2150076d8014ff…
disclosure@vulncheck.com
https://www.vulncheck.com/advisories/pybars4-through-0.9.13-code-injection-via-…
disclosure@vulncheck.com