GHSA-2464-8j7c-4cjm

    Dashboard / Vulnerabilities / GHSA-2464-8j7c-4cjm

    GHSA-2464-8j7c-4cjm

    Published: 21 Aug 2025Last Modified: 10 Sept 2026

    Summary: go-viper's mapstructure May Leak Sensitive Information in Logs When Processing Malformed Data

    Details: ### Summary Use of this library in a security-critical context may result in leaking sensitive information, if used to process sensitive fields. ### Details OpenBao (and presumably HashiCorp Vault) have surfaced error messages from `mapstructure` as follows: https://github.com/openbao/openbao/blob/98c3a59c040efca724353ca46ca79bd5cdbab920/sdk/framework/field_data.go#L43-L50 ```go _, _, err := d.getPrimitive(field, schema) if err != nil { return fmt.Errorf("error converting input for field %q: %w", field, err) } ``` where this calls `mapstructure.WeakDecode(...)`: https://github.com/openbao/openbao/blob/98c3a59c040efca724353ca46ca79bd5cdbab920/sdk/framework/field_data.go#L181-L193 ```go func (d *FieldData) getPrimitive(k string, schema *FieldSchema) (interface{}, bool, error) { raw, ok := d.Raw[k] if !ok { return nil, false, nil } switch t := schema.Type; t { case TypeBool: var result bool if err := mapstructure.WeakDecode(raw, &result); err != nil { return nil, false, err } return result, true, nil ``` Notably, `WeakDecode(...)` eventually calls one of the decode helpers, which surfaces the original value via `strconv` helpers: https://github.com/go-viper/mapstructure/blob/8c61ec1924fcfa522f9fc6b4618c672db61d1a38/mapstructure.go#L720-L727 https://github.com/go-viper/mapstructure/blob/8c61ec1924fcfa522f9fc6b4618c672db61d1a38/mapstructure.go#L791-L798 https://github.com/go-viper/mapstructure/blob/8c61ec1924fcfa522f9fc6b4618c672db61d1a38/decode_hooks.go#L180 & more. These are different code paths than are fixed in the previous iteration at https://github.com/go-viper/mapstructure/security/advisories/GHSA-fv92-fjc5-jj9h. ### PoC To reproduce with OpenBao: ``` $ podman run --pull=always -p 8300:8300 openbao/openbao:latest server -dev -dev-root-token-id=root -dev-listen-address=0.0.0.0:8300 ``` and in a new tab: ``` $ BAO_TOKEN=root BAO_ADDR=http://localhost:8300 bao auth enable userpass Success! Enabled userpass auth method at: userpass/ $ curl -X PUT -H "X-Vault-Request: true" -H "X-Vault-Token: root" -d '{"ttl":"asdf"}' "http://localhost:8200/v1/auth/userpass/users/asdf" --> server logs: 2025-06-25T21:32:25.101-0500 [ERROR] core: failed to run existence check: error="error converting input for field \"ttl\": time: invalid duration \"asdf\"" ``` ### Impact This is an information disclosure bug with little mitigation. See https://discuss.hashicorp.com/t/hcsec-2025-09-vault-may-expose-sensitive-information-in-error-logs-when-processing-malformed-data-with-the-kv-v2-plugin/74717 for a previous version. That version was fixed, but this is in the second part of that error message (starting at `'' expected a map, got 'string'` -- when the field type is `string` and a `map` is provided, we see the above information leak -- the previous example had a `map` type field with a `string` value provided). This was rated 4.5 Medium by HashiCorp in the past iteration.

    Affected packages

    Package

    Name: github.com/go-viper/mapstructure/v2

    Purl: pkg:golang/github.com/go-viper/mapstructure/v2

    Affected ranges

    Type: SEMVER

    Events:

    Introduced- 0
    Fixed -2.4.0

    Affected versions

    Common Vulnerability Scoring System

    Attack Vector
    Network
    Adjacent
    Local
    Physical
    Privileges Required
    None
    Low
    High
    User Interaction
    None
    Required
    Scope
    Unchanged
    Changed
    Confidentiality
    None
    Low
    High
    Integrity
    None
    Low
    High
    Availability
    None
    Low
    High