# CVE-2018-16477: Exposure of Sensitive Information to an Unauthorized Actor in activestorage

> Attackers can execute inline HTML via Active Storage bypass, potentially accessing private signed URLs and causing XSS.

- **Severity:** Medium 6.5 (`CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 30 Nov 2018
- **Updated:** 5 Aug 2024
- **Also known as:** DEBIAN-CVE-2018-16477, GHSA-7rr7-rcjw-56vj

## What is CVE-2018-16477?

CVE-2018-16477 is a medium-severity cross-site scripting vulnerability in Rubyonrails Rails, published on 30 Nov 2018. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

A bypass vulnerability in Active Storage >= 5.2.0 for Google Cloud Storage and Disk services allow an attacker to modify the `content-disposition` and `content-type` parameters which can be used in with HTML files and have them executed inline. Additionally, if combined with other techniques such as cookie bombing and specially crafted AppCache manifests, an attacker can gain access to private signed URLs within a specific storage path. This vulnerability has been fixed in version 5.2.1.1.

Weakness: CWE-200 (Exposure of Sensitive Information to an Unauthorized Actor)

## Which versions are affected by CVE-2018-16477?

2 open source packages ship an affected version, including activestorage. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `activestorage` | RubyGems | From 5.2.0 | 5.2.1.1 |
| `activestorage` | RubyGems | From 5.2.0 | 5.2.1.1 |

Products: Rubyonrails Rails.

## How do I fix CVE-2018-16477?

Upgrade activestorage to 5.2.1.1 or later.

## Is CVE-2018-16477 being exploited?

There is no known exploitation of CVE-2018-16477 in the wild and no public exploit code.

## Other vulnerabilities in Rubyonrails Rails

- [CVE-2013-0277](https://insights.sbomify.com/CVE-2013-0277/): Active Record contains deserialization of arbitrary YAML (critical 10.0)
- [CVE-2017-17916](https://insights.sbomify.com/CVE-2017-17916/): SQL injection in n/a (high 8.1)
- [CVE-2017-17917](https://insights.sbomify.com/CVE-2017-17917/): SQL injection in n/a (high 8.1)
- [CVE-2026-33195](https://insights.sbomify.com/CVE-2026-33195/): Rails Active Storage has possible Path Traversal in DiskService (high 8.0)
- [CVE-2024-26142](https://insights.sbomify.com/CVE-2024-26142/): Rails possible ReDoS vulnerability in Accept header parsing in Action Dispatch (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2018-16477 and fix it if it is affected.

What it is: CVE-2018-16477 is a medium-severity cross-site scripting vulnerability in Rubyonrails Rails, published on 30 Nov 2018. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2018-16477 in the wild and no public exploit code.

Affected packages and fixed versions:
- activestorage (RubyGems): affected from 5.2.0; fixed in 5.2.1.1
- activestorage (RubyGems): affected from 5.2.0; fixed in 5.2.1.1

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-2018-16477/ (Markdown: https://insights.sbomify.com/CVE-2018-16477/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2018-16477
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-16477
- OSV: https://osv.dev/vulnerability/CVE-2018-16477

---
From sbomify Insights: https://insights.sbomify.com/CVE-2018-16477/
Summaries are generated and may contain mistakes; the official description above is the record.