# What is CVE-2004-0230?

> CVE-2004-0230 is a medium-severity flaw (CVSS 5.0) in Junos from Juniper, published on 18 August 2004. It is not on the list of flaws known to be exploited today. The latest forecast puts its chance of use in the next 30 days at 80%. If you run an affected version, plan in the vendor’s fix.

Canonical page: https://www.precursorintelligence.com/what-is/cve-2004-0230

## At a glance

- **Verdict:** Fix this soon. Not confirmed as exploited yet, but serious or likely enough that it should not wait for a quiet month.
- **Precursor Intelligence risk score:** 56 out of 100 (Medium); action: Plan remediation. Kept up to date as the evidence changes.
- **Severity:** Medium (CVSS 5.0 out of 10)
- **Known to be exploited:** No, not on the list of flaws known to be exploited today
- **Chance of use in the next 30 days:** 80% (latest exploit-likelihood forecast)
- **Published:** 18 August 2004
- **Record last updated:** 16 June 2026
- **Main product:** Junos from Juniper
- **Affected products:** 12

## What is CVE-2004-0230? In plain terms

It can be attacked from anywhere on the internet without logging in. If it works, the attacker can slow it down.

### The official description

TCP, when using a large Window Size, makes it easier for remote attackers to guess sequence numbers and cause a denial of service (connection loss) to persistent TCP connections by repeatedly injecting a TCP RST packet, especially in protocols that use long-lived connections, such as BGP.

### What kind of flaw is it?

- Unknown: Unknown

### How an attack on it works

- Where an attacker can be: Anywhere on the internet
- How hard it is to pull off: Easy: no special conditions
- Login needed first: No login needed
- What an attacker gets: Can slow it down

Severity vector: `AV:N/AC:L/Au:N/C:N/I:N/A:P`

## Is CVE-2004-0230 being exploited? Not that we know of

It is not on the list of flaws known to be exploited today. The latest forecast puts the chance of it being used in the next 30 days at 80%. That can change at any time, which is why we keep watching.

Exploit likelihood over the last 7 days: 80%, 80%, 80%, 80%, 80%, 80%, 80%.

### Timeline

- 18 August 2004: Published
- 7 March 2023: Exploit likelihood fell
- 17 December 2024: Exploit likelihood jumped
- 16 June 2026: Record last updated

### How Precursor Intelligence ranks it

CVE-2004-0230 scores **56 out of 100 (Medium)**, with the action "Plan remediation".

Every published flaw gets a risk score from 0 to 100, kept up to date as the evidence changes. Four things go into the score, from the one that counts most to the ones that count less:

- Evidence it is being exploited: biggest factor
- How severe it is: strong factor
- How widely exposed it is: smaller factor
- Threat activity around it: smaller factor

85 and above is Critical. Anything confirmed as exploited is always marked for an emergency patch, whatever its score. When this flaw matches software you track, it lands in your list with its score and the reasons behind it.

## Who is affected by CVE-2004-0230?

The published record lists 12 products. Versions are as published: "before 11.4" means every version up to, but not including, 11.4.

- [Junos](https://www.precursorintelligence.com/product/juniper/junos) by [Juniper](https://www.precursorintelligence.com/vendors/juniper) (Operating system): before 11.4, 11.4, 11.4-r1, 11.4-r2, 11.4-r3, 11.4-r4, 11.4-r5, 11.4-r6, 11.4-r7, 11.4-r8, 11.4-r9, 11.4-r10, 11.4r13-s2, 11.4x27, 12.1, 12.1r, 12.1x44, 12.1x44-d10, 12.1x44-d15, 12.1x44-d20, 12.1x44-d25, 12.1x44-d30, 12.1x44-d35, 12.1x45, 12.1x45-d10, 12.1x45-d15, 12.1x45-d20, 12.1x46, 12.1x46-d10, 12.1x46-d15, 12.1x47, 12.2, 12.2-r1, 12.2-r2, 12.2-r3, 12.2-r4, 12.2-r5, 12.2-r6, 12.2-r7, 12.3 and 15 more
- [NetBSD](https://www.precursorintelligence.com/product/netbsd/netbsd) by [NetBSD](https://www.precursorintelligence.com/vendors/netbsd) (Operating system): 1.5, 1.5.1, 1.5.2, 1.5.3, 1.6, 1.6.1, 1.6.2, 2.0
- [Network Data Loss Prevention](https://www.precursorintelligence.com/product/mcafee/network_data_loss_prevention) by [Mcafee](https://www.precursorintelligence.com/vendors/mcafee) (Application): up to 8.6, 9.2.0, 9.2.1, 9.2.2
- [Openserver](https://www.precursorintelligence.com/product/xinuos/openserver) by [Xinuos](https://www.precursorintelligence.com/vendors/xinuos) (Operating system): 5.0.6, 5.0.7
- [Solaris](https://www.precursorintelligence.com/product/oracle/solaris) by [Oracle](https://www.precursorintelligence.com/vendors/oracle) (Operating system): 10, 11
- [Unixware](https://www.precursorintelligence.com/product/xinuos/unixware) by [Xinuos](https://www.precursorintelligence.com/vendors/xinuos) (Operating system): 7.1.1, 7.1.3
- [Openpgp](https://www.precursorintelligence.com/product/openpgp/openpgp) by [Openpgp](https://www.precursorintelligence.com/vendors/openpgp) (Application): 2.6.2
- [Windows 2000](https://www.precursorintelligence.com/product/microsoft/windows_2000) by [Microsoft](https://www.precursorintelligence.com/vendors/microsoft) (Operating system): version not specified
- [Windows 98](https://www.precursorintelligence.com/product/microsoft/windows_98) by [Microsoft](https://www.precursorintelligence.com/vendors/microsoft) (Operating system): version not specified
- [Windows 98se](https://www.precursorintelligence.com/product/microsoft/windows_98se) by [Microsoft](https://www.precursorintelligence.com/vendors/microsoft) (Operating system): version not specified
- [Windows Server 2003](https://www.precursorintelligence.com/product/microsoft/windows_server_2003) by [Microsoft](https://www.precursorintelligence.com/vendors/microsoft) (Operating system): version not specified
- [Windows Xp](https://www.precursorintelligence.com/product/microsoft/windows_xp) by [Microsoft](https://www.precursorintelligence.com/vendors/microsoft) (Operating system): version not specified

## How do I fix CVE-2004-0230?

1. **Check whether you run it.** Compare your versions with the affected products above. Not sure what you run? Precursor Intelligence can work it out from your public website, or you can pick it from a list.
2. **Apply the vendor’s fix.** Install the update named in the vendor’s advisory. We’ve put the advisories and patch notes first in the list.
3. **If you can’t patch today.** Follow any mitigation the vendor publishes, and limit who can reach the affected system from the internet until the update is in.
4. **Keep an eye on it.** Track the product and we tell you as soon as we spot this flaw on the list of exploited flaws, or a jump in its exploit likelihood.

### References

- [oracle.com](http://www.oracle.com/technetwork/topics/security/cpujan2015-1972971.html) (Patch, Third-party advisory)
- [kc.mcafee.com](https://kc.mcafee.com/corporate/index?page=content&id=SB10053) (Broken link, Patch, Third-party advisory)
- [kb.juniper.net](http://kb.juniper.net/JSA10638) (Third-party advisory)
- [marc.info](http://marc.info/?l=bugtraq&m=108302060014745&w=2) (Mailing list)
- [marc.info](http://marc.info/?l=bugtraq&m=108506952116653&w=2) (Mailing list)
- [secunia.com](http://secunia.com/advisories/11440) (Broken link, Permissions required, Third-party advisory, Vulnerability database)
- [secunia.com](http://secunia.com/advisories/11458) (Broken link, Permissions required, Third-party advisory, Vulnerability database)
- [secunia.com](http://secunia.com/advisories/22341) (Broken link, Permissions required, Third-party advisory, Vulnerability database)
- [cisco.com](http://www.cisco.com/warp/public/707/cisco-sa-20040420-tcp-ios.shtml) (Broken link)
- [kb.cert.org](http://www.kb.cert.org/vuls/id/415294) (Third-party advisory, Government resource)
- [osvdb.org](http://www.osvdb.org/4030) (Broken link)
- [securityfocus.com](http://www.securityfocus.com/archive/1/449179/100/0/threaded) (Broken link)
- [securityfocus.com](http://www.securityfocus.com/bid/10183) (Exploit, Third-party advisory, Vulnerability database)
- [uniras.gov.uk](http://www.uniras.gov.uk/vuls/2004/236929/index.htm) (Broken link)
- [us-cert.gov](http://www.us-cert.gov/cas/techalerts/TA04-111A.html) (Third-party advisory, Government resource)
- [vupen.com](http://www.vupen.com/english/advisories/2006/3983) (Broken link, Permissions required)
- [docs.microsoft.com](https://docs.microsoft.com/en-us/security-updates/securitybulletins/2005/ms05-019) (Third-party advisory)
- [docs.microsoft.com](https://docs.microsoft.com/en-us/security-updates/securitybulletins/2006/ms06-064) (Third-party advisory)
- [exchange.xforce.ibmcloud.com](https://exchange.xforce.ibmcloud.com/vulnerabilities/15886) (Third-party advisory)
- [oval.cisecurity.org](https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A2689) (Broken link)
- [oval.cisecurity.org](https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A270) (Broken link)
- [oval.cisecurity.org](https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A3508) (Broken link)
- [oval.cisecurity.org](https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A4791) (Broken link)
- [oval.cisecurity.org](https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A5711) (Broken link)

## Questions

### What is CVE-2004-0230?

CVE-2004-0230 is a medium-severity flaw in Junos from Juniper, published on 18 August 2004. It can be attacked from anywhere on the internet without logging in. If it works, the attacker can slow it down.

### How serious is CVE-2004-0230?

It scores 5.0 out of 10 on the CVSS severity scale, which is medium. Our risk score for CVE-2004-0230 is 56 out of 100, which is Medium. Its action is "Plan remediation". Not confirmed as exploited yet, but serious or likely enough that it should not wait for a quiet month.

### Is CVE-2004-0230 being exploited?

It is not on the list of flaws known to be exploited today. The latest forecast puts the chance of it being used in the next 30 days at 80%. That can change at any time, which is why we keep watching.

### Which versions does CVE-2004-0230 affect?

For Junos from Juniper: before 11.4, 11.4, 11.4-r1, 11.4-r2, 11.4-r3, 11.4-r4 and 49 more. The record lists 12 products in all, each with its versions, under "Who is affected" on this page.

### How do I fix CVE-2004-0230?

Install the update the vendor names in its advisory, linked first under "How do I fix" on this page. If you can't patch today, follow the vendor's mitigation and limit who can reach the affected system from the internet.

## Does CVE-2004-0230 affect you?

Precursor Intelligence keeps checking for you:

- **Tell us what you run.** Pick your software from a list, or let us work it out from your website.
- **We match it to every flaw.** Over 400,000 published flaws, checked against your list.
- **Ranked by real-world risk.** Every flaw gets a 0 to 100 risk score, kept up to date, led by evidence criminals are using it.
- **Told as soon as we know.** An alert by email, in the app or by webhook to your own tools.

Start free (no card, nothing to install): https://www.precursorintelligence.com/register
Book a demo: https://www.precursorintelligence.com/contact