Vulnerability in wbond pybars3

[ Why it matters ]Priority signals

• Critical severity: CVSS 9.8

[ Description ]Official description

pybars3 through 0.9.7 and pybars4 through 0.9.13 contain a code injection vulnerability in pybars/_compiler.py that allows template authors to execute Python code via unescaped bracketed path segments. Attackers can supply Handlebars templates with crafted segments in helper or block arguments to break out of string literals and execute Python in the application process.

[ Fixes ]Fixes and patches

No fix or interim patch is linked from our sources yet. Check the vendor references below and limit exposure of affected systems until a fix is available.

[ References ]References

• github.com/up9inc/pybars4
• github.com/up9inc/pybars4/blob/0.9.13/pybars/_compiler.py
• github.com/vladko312/advisories/blob/702e98db9642ece70d9e2150076d8014ffec2db3/pybars3.md
• github.com/wbond/pybars3
• github.com/wbond/pybars3/blob/0.9.7/pybars/_compiler.py
• github.com/wbond/pybars3/issues/88
• www.vulncheck.com/advisories/pybars3-through-0.9.7-code-injection-via-bracketed-path-se…