Vulnerability · Published Sep 4, 2023 · Assigned by GitHub_M
CVE-2023-40015Vyper: reversed order of side effects for some operations
Low 3.7
In plain English
A low-severity security flaw in vyper from vyperlang. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 42% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
Vyper is a Pythonic Smart Contract Language. For the following (probably non-exhaustive) list of expressions, the compiler evaluates the arguments from right to left instead of left to right. `unsafe_add, unsafe_sub, unsafe_mul, unsafe_div, pow_mod256, |, &, ^ (bitwise operators), bitwise_or (deprecated), bitwise_and (deprecated), bitwise_xor (deprecated), raw_call, <, >, <=, >=, ==, !=, in, not in (when lhs and rhs are enums)`. This behaviour becomes a problem when the evaluation of one of the arguments produces side effects that other arguments depend on. The following expressions can produce side-effect: state modifying external call , state modifying internal call, `raw_call`, `pop()` when used on a Dynamic Array stored in the storage, `create_minimal_proxy_to`, `create_copy_of`, `create_from_blueprint`. This issue has not yet been patched. Users are advised to make sure that the arguments of the expression do not produce side effects or, if one does, that no other argument is dependent on those side effects.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| PyPI | vyper | no fix listed | GHSA-g2xh-c426-v8mf |
| PyPI | vyper | 0.3.10rc1 | PYSEC-2023-167 |
Affected products (as reported)
Weakness: CWE-670 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N
References
- https://github.com/vyperlang/vyper/security/advisories/GHSA-g2xh-c426-v8mf x_refsource_CONFIRM