CVE-2023-34449

ink! vulnerable to incorrect decoding of storage value when using `DelegateCall`

MEDIUM
5.3
CVSS Score
Published: June 14, 2023 at 08:10 PM UTC
Updated: June 17, 2026 at 06:03 AM UTC
2 products affected across 2 vendorsInk !Ink

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Severity
MEDIUM5.3
Exploit prediction
EPSS 1.0%
SSVC
PoC

Description

ink! is an embedded domain specific language to write smart contracts in Rust for blockchains built on the Substrate framework. Starting in version 4.0.0 and prior to version 4.2.1, the return value when using delegate call mechanics, either through `CallBuilder::delegate` or `ink_env::invoke_contract_delegate`, is decoded incorrectly. This bug was related to the mechanics around decoding a call's return buffer, which was changed as part of pull request 1450. Since this feature was only released in ink! 4.0.0, no previous versions are affected. Users who have an ink! 4.x series contract should upgrade to 4.2.1 to receive a patch.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

4.0.0 ≤ v < 4.2.1
Affected range stops below 4.2.1, so it looks safe — our inference, not a vendor statement
v < 4.2.1
Affected range stops below 4.2.1, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

SSVC — Action Prioritization

SSVCPoCAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

5.3MEDIUMGitHub_M
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
LOW
Availability
NONE
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-253CWE-754

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