CVE-2022-23495: ipfs go-merkledag

Vulnerability summary

CVE-2022-23495 is a high (CVSS 7.5) vulnerability in ipfs go-merkledag. EPSS estimates a 1.38% chance of exploitation in the next 30 days, higher than 71.7% of scored vulnerabilities.

Timeline

1. 08-12-2022
   PublishedVulnerability first disclosed.
2. 23-04-2025
   Last modifiedVulnerability information updated.

Description

go-merkledag implements the 'DAGService' interface and adds two ipld node types, Protobuf and Raw for the ipfs project. A `ProtoNode` may be modified in such a way as to cause various encode errors which will trigger a panic on common method calls that don't allow for error returns. A `ProtoNode` should only be able to encode to valid DAG-PB, attempting to encode invalid DAG-PB forms will result in an error from the codec. Manipulation of an existing (newly created or decoded) `ProtoNode` using the modifier methods did not account for certain states that would place the `ProtoNode` into an unencodeable form. Due to conformance with the [`github.com/ipfs/go-block-format#Block`](https://pkg.go.dev/github.com/ipfs/go-block-format#Block) and [`github.com/ipfs/go-ipld-format#Node`](https://pkg.go.dev/github.com/ipfs/go-ipld-format#Node) interfaces, certain methods, which internally require a re-encode if state has changed, will panic due to the inability to return an error. This issue has been addressed across a number of pull requests. Users are advised to upgrade to version 0.8.1 for a complete set of fixes. Users unable to upgrade may attempt to mitigate this issue by sanitising inputs when allowing user-input to set a new `CidBuilder` on a `ProtoNode` and by sanitising `Tsize` (`Link#Size`) values such that they are a reasonable byte-size for sub-DAGs where derived from user-input.

• CWE-755Improper Handling of Exceptional ConditionsThe product does not handle or incorrectly handles an exceptional condition.
• CWE-252Unchecked Return ValueThe product does not check the return value from a method or function, which can prevent it from detecting unexpected states and conditions.