Vyper has incorrectly allocated named re-entrancy locks

CVE-2023-39363 → View on GitHub ↗ View on CVE.org ↗ View on NVD ↗

Description

Impact

In versions 0.2.15, 0.2.16 and 0.3.0, named re-entrancy locks are allocated incorrectly. Each function using a named re-entrancy lock gets a unique lock regardless of the key, allowing cross-function re-entrancy in contracts compiled with the susceptible versions. A specific set of conditions is required to result in misbehavior of affected contracts, specifically:

  • A .vy contract compiled with either of the following vyper versions: 0.2.15, 0.2.16, 0.3.0
  • A primary function that utilizes the @nonreentrant decorator with a specific key and does not strictly follow the check-effects-interaction pattern (i.e. contains an external call to an untrusted party before storage updates)
  • A secondary function that utilizes the same key and would be affected by the improper state caused by the primary function

Patches

https://github.com/vyperlang/vyper/pull/2439, https://github.com/vyperlang/vyper/pull/2514

Workarounds

Upgrade to 0.3.1 or higher

References

Technical post-mortem report: https://hackmd.io/@vyperlang/HJUgNMhs2

Basic information

Type
reviewed
Severity
critical
Advisory on GitHub
Open advisory ↗
Repository advisory
Open repository advisory ↗
Source code
Browse source ↗
Published (advisory)
2023-08-09 14:27:57 UTC
Updated
2024-10-11 14:04:47 UTC
GitHub reviewed
2023-08-09 14:27:57 UTC
NVD published
2023-08-07

EPSS Score

Score Percentile
0.07% 22.17%

CVSS Scores

Base score Version Severity Vector
8.7 3.1 —
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
9.1 4.0 —
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:H/SC:N/SI:H/SA:H/E:A Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network.
Attack complexity (AC:L)
Exploitation conditions are straightforward and stable.
Attack requirements (AT:P)
Additional preconditions must be present for exploitation.
Privileges required (PR:N)
No privileges are required.
User interaction (UI:N)
No user interaction is required.
Vulnerable system confidentiality impact (VC:N)
No confidentiality impact on the vulnerable system.
Vulnerable system integrity impact (VI:H)
High integrity impact on the vulnerable system.
Vulnerable system availability impact (VA:H)
High availability impact on the vulnerable system.
Subsequent system confidentiality impact (SC:N)
No confidentiality impact on subsequent systems.
Subsequent system integrity impact (SI:H)
High integrity impact on subsequent systems.
Subsequent system availability impact (SA:H)
High availability impact on subsequent systems.
Exploit maturity (threat) (E:A)
Attacked: exploitation has been reported, or toolkits exist that simplify exploitation.

Identifiers

Type Value
GHSA GHSA-5824-cm3x-3c38 ↗
CVE CVE-2023-39363 ↗

CWEs

CWE id Name
CWE-863 Incorrect Authorization

Credits

  • trocher (analyst)

Affected packages (1)

Vulnerable version ranges and first patched releases as published by GitHub.

Ecosystem Package Vulnerable range First patched Vulnerable functions
pip vyper >= 0.2.15, < 0.3.1 0.3.1 —

References

cvelogic Threat Intelligence