evm: Always-Incorrect Control Flow Implementation
CVE-2022-39354 is a high-severity always-incorrect control flow implementation vulnerability in evm from Rust-blockchain, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected evm versions: < 0.36.0. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.7% chance of exploitation within 30 days, higher than 54% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of evm you run against the affected versions below, and install the vendor's latest release.
- Read the advisory on github.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Rust-blockchain | evm | < 0.36.0 | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- NoneNo data is disclosed.
- Integrity
- HighData or code can be modified at will.
- Availability
- NoneAvailability is not affected.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 5.9 | Medium | CNA (github.com) |
| CVSS 3.1 | 7.5 | High | NVD |
Official description
SputnikVM, also called evm, is a Rust implementation of Ethereum Virtual Machine. A custom stateful precompile can use the `is_static` parameter to determine if the call is executed in a static context (via `STATICCALL`), and thus decide if stateful operations should be done. Prior to version 0.36.0, the passed `is_static` parameter was incorrect -- it was only set to `true` if the call came from a direct `STATICCALL` opcode. However, once a static call context is entered, it should stay static. The issue only impacts custom precompiles that actually uses `is_static`. For those affected, the issue can lead to possible incorrect state transitions. Version 0.36.0 contains a patch. There are no known workarounds.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Always-Incorrect Control Flow Implementation
The code contains a control flow path that does not reflect the algorithm that the path is intended to implement, leading to incorrect behavior any time this path is navigated.
More Always-Incorrect Control Flow Implementation vulnerabilities (CWE-670)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Advisories
- github.com/rust-blockchain/evm/security/advisories/GHSA-hhc4-47rh-cr34Third Party Advisory
Patches and release notes
- github.com/rust-blockchain/evm/pull/133Third Party Advisory
Recent Always-Incorrect Control Flow Implementation vulnerabilities
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 9.8 Critical severity
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