Headline
GHSA-xchq-w5r3-4wg3: vyper performs incorrect topic logging in raw_log
Summary
Incorrect values can be logged when raw_log builtin is called with memory or storage arguments to be used as topics.
A contract search was performed and no vulnerable contracts were found in production. In particular, no uses of raw_log() were found at all in production; it is apparently not a well-known function.
Details
The build_IR function of the RawLog class fails to properly unwrap the variables provided as topics. Consequently, incorrect values are logged as topics.
PoC
x: bytes32
@external
def f():
self.x = 0x1234567890123456789012345678901234567890123456789012345678901234
raw_log([self.x], b"") # LOG1(offset:0x60, size:0x00, topic1:0x00)
y: bytes32 = 0x1234567890123456789012345678901234567890123456789012345678901234
raw_log([y], b"") # LOG1(offset:0x80, size:0x00, topic1:0x40)
Impact
Incorrect values can be logged which may result in unexpected behavior in client-side applications relying on these logs.
Summary
Incorrect values can be logged when raw_log builtin is called with memory or storage arguments to be used as topics.
A contract search was performed and no vulnerable contracts were found in production. In particular, no uses of raw_log() were found at all in production; it is apparently not a well-known function.
Details
The build_IR function of the RawLog class fails to properly unwrap the variables provided as topics. Consequently, incorrect values are logged as topics.
PoC
x: bytes32
@external def f(): self.x = 0x1234567890123456789012345678901234567890123456789012345678901234 raw_log([self.x], b"") # LOG1(offset:0x60, size:0x00, topic1:0x00)
y: bytes32 \= 0x1234567890123456789012345678901234567890123456789012345678901234
raw\_log(\[y\], b"") \# LOG1(offset:0x80, size:0x00, topic1:0x40)
Impact
Incorrect values can be logged which may result in unexpected behavior in client-side applications relying on these logs.
References
- GHSA-xchq-w5r3-4wg3
- https://nvd.nist.gov/vuln/detail/CVE-2024-32645