# CVE-2025-0693: Issue with AWS Sign-in IAM User Login Flow - Possible Username Enumeration

> Attackers can enumerate valid IAM usernames in AWS accounts by analyzing variable response times during the login flow.

- **Severity:** Medium 6.9 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 23 Jan 2025
- **Updated:** 14 Oct 2025
- **Also known as:** GHSA-8rcr-h4v8-qpq5

## What is CVE-2025-0693?

CVE-2025-0693 is a medium-severity vulnerability in AWS Sign-in IAM Login Flow, published on 23 Jan 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Variable response times in the AWS Sign-in IAM user login flow allowed for the use of brute force enumeration techniques to identify valid IAM usernames in an arbitrary AWS account.

Weakness: CWE-208 (Observable Timing Discrepancy), CWE-204 (Observable Response Discrepancy)

## Which versions are affected by CVE-2025-0693?


## How do I fix CVE-2025-0693?

No fix has been published for CVE-2025-0693 yet. Limit exposure of the affected software until one is available.

## Is CVE-2025-0693 being exploited?

There is no known exploitation of CVE-2025-0693 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-0693 and fix it if it is affected.

What it is: CVE-2025-0693 is a medium-severity vulnerability in AWS Sign-in IAM Login Flow, published on 23 Jan 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2025-0693 in the wild and no public exploit code.

Affected product: AWS Sign-in IAM Login Flow. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2025-0693/ (Markdown: https://insights.sbomify.com/CVE-2025-0693/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-0693
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-0693
- OSV: https://osv.dev/vulnerability/CVE-2025-0693

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From sbomify Insights: https://insights.sbomify.com/CVE-2025-0693/
Summaries are generated and may contain mistakes; the official description above is the record.