# CVE-2004-2491: Other in n/a

> Remote attackers can spoof the address bar URL via a race condition, facilitating phishing attacks against Opera browser users.

- **Severity:** Low 2.6 (`AV:N/AC:H/Au:N/C:N/I:P/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:** No
- **Published:** 25 Oct 2005
- **Updated:** 8 Aug 2024
- **Also known as:** GHSA-6rch-h7pj-5838

## What is CVE-2004-2491?

CVE-2004-2491 is a low-severity vulnerability in Opera Opera Browser, published on 25 Oct 2005. 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 race condition in Opera web browser 7.53 Build 3850 causes Opera to fill in the address bar before the page has been loaded, which allows remote attackers to spoof the URL in the address bar via the window.open and location.replace HTML parameters, which facilitates phishing attacks.

Weakness: CWE-362 (Concurrent Execution using Shared Resource with Improper Synchronization)

## Which versions are affected by CVE-2004-2491?

It affects 1 product.


Products: Opera Opera Browser.

## How do I fix CVE-2004-2491?

No fix has been published for CVE-2004-2491 yet. Limit exposure of the affected software until one is available.

## Is CVE-2004-2491 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2004-2491 exists.

Public exploit code:

- Opera Web Browser 7.53 - Location Replace URI Obfuscation (exploitdb)

## Other vulnerabilities in Opera Opera Browser

- [CVE-2013-3211](https://insights.sbomify.com/CVE-2013-3211/): Unspecified vulnerability in Opera before 12.15 has unknown impact and attack vectors, related to a "moderately severe issue." (critical 10.0)
- [CVE-2012-4145](https://insights.sbomify.com/CVE-2012-4145/): Other in n/a (critical 10.0)
- [CVE-2012-3559](https://insights.sbomify.com/CVE-2012-3559/): Other in n/a (critical 10.0)
- [CVE-2012-3561](https://insights.sbomify.com/CVE-2012-3561/): Memory corruption in n/a (critical 10.0)
- [CVE-2011-4683](https://insights.sbomify.com/CVE-2011-4683/): Unspecified vulnerability in Opera before 11.60 has unknown impact and attack vectors, related to a "moderately severe issue." (critical 10.0)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2004-2491 and fix it if it is affected.

What it is: CVE-2004-2491 is a low-severity vulnerability in Opera Opera Browser, published on 25 Oct 2005. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2004-2491 exists.

Affected product: Opera Opera Browser. 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-2004-2491/ (Markdown: https://insights.sbomify.com/CVE-2004-2491/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2004-2491
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2004-2491
- OSV: https://osv.dev/vulnerability/CVE-2004-2491

---
From sbomify Insights: https://insights.sbomify.com/CVE-2004-2491/
Summaries are generated and may contain mistakes; the official description above is the record.