HOMEVULNERABILITIESCVE-2004-2491
LOWPOC

CVE-2004-2491

CWE-362Published: December 31, 2004· Updated: Jun 16, 2026

2.6
CVSS v3.1

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.

NVD Source

Technical Analysis

CVE-2004-2491 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

Exploitation requires some privileges, which limits the exposure to scenarios where an attacker has already gained initial access.

A proof-of-concept (PoC) exploit exists for CVE-2004-2491. While not yet confirmed in active campaigns, the availability of PoC code increases exploitation risk substantially.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorNetwork
Attack ComplexityHigh
Privileges Req.
User Interaction
Scope
Impact
ConfidentialityNone
IntegrityP
AvailabilityNone
AV:N/AC:H/Au:N/C:N/I:P/A:N

Affected Vendors & Products

opera1 product(s)
opera browser
Source: NVD CPE · 1 total CPE entries

Exploit & PoC Resources

POC AVAILABLEProof-of-concept code exists
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

PATCHhttp://secunia.com/advisories/12162
PATCHhttp://www.opera.com/windows/changelogs/754/
PATCHhttp://www.securityfocus.com/bid/10810
PATCHhttp://secunia.com/advisories/12162
PATCHhttp://www.opera.com/windows/changelogs/754/
PATCHhttp://www.securityfocus.com/bid/10810
ADVISORYhttps://exchange.xforce.ibmcloud.com/vulnerabilities/16816
ADVISORYhttps://exchange.xforce.ibmcloud.com/vulnerabilities/16816

All References (12)

→
http://archives.neohapsis.com/archives/fulldisclosure/2004-07/1056.htmlBroken Link · Exploit
→
http://secunia.com/advisories/12162Broken Link · Patch
→
http://www.opera.com/windows/changelogs/754/Broken Link · Patch
→
http://www.osvdb.org/8317Broken Link · Exploit
→
http://www.securityfocus.com/bid/10810Broken Link · Exploit · Patch · Third Party Advisory · VDB Entry
→
https://exchange.xforce.ibmcloud.com/vulnerabilities/16816Third Party Advisory · VDB Entry
→
http://archives.neohapsis.com/archives/fulldisclosure/2004-07/1056.htmlBroken Link · Exploit
→
http://secunia.com/advisories/12162Broken Link · Patch
→
http://www.opera.com/windows/changelogs/754/Broken Link · Patch
→
http://www.osvdb.org/8317Broken Link · Exploit
→
http://www.securityfocus.com/bid/10810Broken Link · Exploit · Patch · Third Party Advisory · VDB Entry
→
https://exchange.xforce.ibmcloud.com/vulnerabilities/16816Third Party Advisory · VDB Entry

Quick Facts

CVE IDCVE-2004-2491
CVSS Score2.6 / 10
SeverityLOW
WeaknessCWE-362
CISA KEVNo
ExploitPOC
Affected1 vendor(s)
PublishedDec 31, 2004

Related CVEs (CWE-362)

CVE-2010-1228
10.0
CVE-2015-8556
10.0
CVE-2008-6598
10.0
CVE-2014-0703
10.0
CVE-2020-1660
9.9
CVE-2025-48751
9.8

Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2004-2491 in threat intel feeds
  • →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWatch. CVE data is provided under the NVD usage policy.
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