# Oracle denomination or decimal conversion is incorrect

The consumer mixes quote currencies, token precision or feed precision and assigns the wrong economic value.

**Candidate CWE:** [CWE-682](https://cwe.mitre.org/data/definitions/682.html)

## Test hypothesis

Use local mock feeds representing equal economic prices at supported decimal scales. Compare against an independent unit-aware calculation and the normal supported feed baseline.

## Evidence required

Feed address/type assumptions, currency pair, feed/token decimals, exact conversion and downstream value discrepancy.

## Rule out false positives

Changing a feed to an unsupported format solely through administrator control is not necessarily an attacker-reachable vulnerability.

## Playbook and command references

- [Contract signatures and oracles: context, freshness and units](https://bug-bounty-field-manual.kmahshooq.chatgpt.site/modules/contract-signatures-oracles.html) — Test signed-action context and price-consumer assumptions with local keys, mock feeds and explicit negative controls.

[Find the associated command snippets](https://bug-bounty-field-manual.kmahshooq.chatgpt.site/commands.html?q=Contract%20signatures%20and%20oracles%3A%20context%2C%20freshness%20and%20units)

## Referenced by these target playbooks

[Web3 & protocols](https://bug-bounty-field-manual.kmahshooq.chatgpt.site/web3.html) · [OSS & self-hosted](https://bug-bounty-field-manual.kmahshooq.chatgpt.site/oss.html)

## Report checklist

- [ ] Capture the affected version, configuration, identities, and object ownership.
- [ ] Preserve a valid baseline and a negative control.
- [ ] Reproduce the forbidden data access, action, or state change on controlled fixtures.
- [ ] Explain the intended security rule and why the observed behavior violates it.
- [ ] State prerequisites, uncertainty, cleanup, and the smallest demonstrated impact.

## Conditional ATT&CK mapping

No direct ATT&CK mapping selected. Record the weakness and demonstrated impact without forcing an adversary-behavior classification. See the [mapping guide](https://bug-bounty-field-manual.kmahshooq.chatgpt.site/attack.html).

## Primary references

- [Chainlink Data Feeds API](https://docs.chain.link/data-feeds/api-reference)

[Back to the complete vulnerability catalog](https://bug-bounty-field-manual.kmahshooq.chatgpt.site/vulnerabilities.html)