add vyper version detector

docs/curve_vyper_reentrancy.md

@@ -0,0 +1,26 @@
+# Curve Readonly Reentrancy
+
+## Configuration
+
+- Check: `pess-curve-vyper-reentrancy`
+- Severity: `High`
+- Confidence: `High`
+
+## Description
+
+Finds if the code is compiled with vulnerable Vyper compiler version and contains non-reentrant modifiers. 
+Details:
+- [Curve exploit postmortem](https://hackmd.io/@LlamaRisk/BJzSKHNjn)
+- [Postmortem from Vyper team](https://hackmd.io/@vyperlang/HJUgNMhs2)
+
+## Vulnerable Scenario
+
+[test scenarios](../../tests/vyper/curve_vyper_reentrancy_test.vy)
+
+## Related Attacks
+
+- [Vyper compiler exploits](https://www.halborn.com/blog/post/explained-the-vyper-bug-hack-july-2023)
+
+## Recomendations
+
+- Upgrade the version of your Vyper compiler.

slitherin/__init__.py

@@ -32,6 +32,7 @@
 from slitherin.detectors.arbitrum.arbitrum_chainlink_price_feed import ArbitrumChainlinkPriceFeed
 from slitherin.detectors.potential_arith_overflow import PotentialArithmOverflow
 from slitherin.detectors.curve.curve_readonly_reentrancy import CurveReadonlyReentrancy
+from slitherin.detectors.vyper.reentrancy_curve_vyper_version import CurveVyperReentrancy
 
 artbitrum_detectors = [
  ArbitrumPrevrandaoDifficulty,
@@ -65,6 +66,7 @@
  AAVEFlashloanCallbackDetector,
  PotentialArithmOverflow,
  CurveReadonlyReentrancy,
+ CurveVyperReentrancy
 ]
 plugin_printers = []
 

slitherin/detectors/vyper/reentrancy_curve_vyper_version.py

@@ -0,0 +1,44 @@
+from typing import List
+from slither.utils.output import Output
+from slither.detectors.abstract_detector import AbstractDetector, DetectorClassification
+from slither.core.declarations import Function
+from slither.slithir.operations.event_call import EventCall
+
+VULNERABLE_VERSIONS = ['0.2.15', '0.2.16', '0.3.0']
+class CurveVyperReentrancy(AbstractDetector):
+ """
+ Sees if contract setters do not emit events
+ """
+
+ ARGUMENT = 'pess-curve-vyper-reentrancy' # slither will launch the detector with slither.py --detect mydetector
+ HELP = f'Vyper compiler versions {", ".join(VULNERABLE_VERSIONS)} are vulnerable to malfunctioning re-entrancy guards. Upgrade your compiler version.'
+ IMPACT = DetectorClassification.HIGH
+ CONFIDENCE = DetectorClassification.HIGH
+
+ WIKI = 'https://github.com/pessimistic-io/slitherin/blob/master/docs/curve_vyper_reentrancy.md'
+ WIKI_TITLE = 'Vulnerable Vyper version'
+ WIKI_DESCRIPTION = "Some Vyper versions are vulnerable to malfunctioning re-entrancy guards."
+ WIKI_EXPLOIT_SCENARIO = 'https://hackmd.io/@LlamaRisk/BJzSKHNjn'
+ WIKI_RECOMMENDATION = 'Upgrade the version of your Vyper compiler.'
+
+ def _detect(self) -> List[Output]:
+ res = []
+ if not self.compilation_unit.is_vyper:
+ return res
+ compiler_version = self.compilation_unit.compiler_version.version
+ if compiler_version not in VULNERABLE_VERSIONS:
+ return res
+
+ for contract in self.contracts:
+ for f in contract.functions_entry_points:
+ for modifier in f.modifiers:
+ if modifier.name.startswith("nonreentrant"):
+ res += ["\t", modifier.name, " in ", f, " function.\n"]
+ if not res:
+ return res
+ return [self.generate_result(
+ [f"Vyper {compiler_version} compiler version is vulnerable to malfunctioning re-entrancy guards. Found vulnerable usages:\n",
+ *[x for x in res],
+ "\n"
+ ]
+ )]

tests/vyper/curve_vyper_reentrancy_test.vy

@@ -0,0 +1,15 @@
+# @version =0.2.15
+
+@external
+@nonreentrant("hello_lock")
+def helloWorld() -> String[24]:
+ return "Hello World!"
+
+@external
+@nonreentrant("another_lock")
+def another_reentrant_func() -> uint256:
+ return 1
+
+@external
+def normal_func() -> uint256:
+ return 0