What is CVE-2003-0300?A medium-severity flaw in Sylpheed Email Client, explained.
CVE-2003-0300 is a medium-severity flaw (CVSS 5.0) in Sylpheed Email Client, published on 16 June 2003. 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 3.4%. If you run an affected version, plan in the vendor’s fix.
Published 16 June 2003. Record last updated 16 June 2026. We keep this page's data up to date.
What is CVE-2003-0300? 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 IMAP Client for Sylpheed 0.8.11 allows remote malicious IMAP servers to cause a denial of service (crash) via certain large literal size values that cause either integer signedness errors or integer overflow errors.
What kind of flaw is it?
- UnknownUnknown
How an attack on it works
Read straight from its severity rating, translated out of the shorthand.
- Where an attacker can beAnywhere on the internet
- How hard it is to pull offEasy: no special conditions
- Login needed firstNo login needed
- What an attacker getsCan slow it down
Severity vector: AV:N/AC:L/Au:N/C:N/I:N/A:P
Is CVE-2003-0300 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 3.4%. That can change at any time, which is why we keep watching.
Timeline
- Published
- Exploit likelihood fell
- Exploit likelihood jumped
- Record last updated
CVE-2003-0300 scores 21. Action: Monitor.
We keep the score of every published flaw up to date as the evidence changes. Four things go into the score, and evidence that criminals are actually using it counts most. In order:
- Evidence it is being exploitedBiggest factor
- How severe it isStrong factor
- How widely exposed it isSmaller factor
- Threat activity around itSmaller factor
85 and above is Critical. Anything confirmed as exploited is always marked for an emergency patch, whatever its score.
When CVE-2003-0300 matches software you track, it lands in your list with its score and the reasons behind it.
See your own ranked list →Who is affected by CVE-2003-0300? 8 products.
The published record lists 8 products from 8 vendors. If you run one of these, check your version, then go to the fix below.
- Application
Sylpheed Email Client
by Sylpheed
Affected versions0.8.11 - Application
Mozilla
by Mozilla
Affected versions1.31.4-alpha - Application
Balsa
Affected versions2.0.10 - Application
Eudora
by Qualcomm
Affected versions5.2.1 - Application
Evolution
by Ximian
Affected versions1.2.4 - Application
Mutt
by Mutt
Affected versions1.4.1 - Application
Outlook Express
by Microsoft
Affected versions6.00.2800.1106 - Application
Pine
Affected versions4.53
How do I fix CVE-2003-0300? Four steps.
- Check whether you run itCompare 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.
- Apply the vendor’s fixInstall the latest update from the vendor. The references list where the vendor has published details.
- If you can’t patch todayFollow any mitigation the vendor publishes, and limit who can reach the affected system from the internet until the update is in.
- Keep an eye on itTrack 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
1 linkDoes CVE-2003-0300 affect you? We'll keep checking.
Looking flaws up one at a time doesn't scale. Tell us what you run once, and we tell you which flaws matter to you, in what order, and keep watching for new ones.
- Tell us what you runPick your software from a list, or let us work it out from your website.
- We match it to every flawOver 400,000 published flaws, checked against your list.
- Ranked by real-world riskA 0 to 100 score, led by evidence criminals are using it.
- Told as soon as we knowAn alert by email, in the app or by webhook to your own tools.
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1 new flaw affects software Acme tracks
The IMAP Client for Sylpheed 0.8.11 allows remote malicious IMAP servers to cause a denial of service (crash) via certain large literal size values that caus...
- Matched to
- Sylpheed Email Client on Acme's software list
- What to do
- Plan in the vendor’s update
Sent to the alert recipients Acme chose. Also in the app and to Acme's webhook.
CVE-2003-0300 is a medium-severity flaw in Sylpheed Email Client, published on 16 June 2003. It can be attacked from anywhere on the internet without logging in. If it works, the attacker can slow it down.
It scores 5.0 out of 10 on the CVSS severity scale, which is medium. Our risk score for CVE-2003-0300 is 21 out of 100, which is Low. Its action is "Monitor". No sign of exploitation and a low forecast. Patch it in your normal update cycle.
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 3.4%. That can change at any time, which is why we keep watching.
For Sylpheed Email Client: 0.8.11. The record lists 8 products in all, each with its versions, under "Who is affected" on this page.
Install the update the vendor names in its advisory. If you can't patch today, follow the vendor's mitigation and limit who can reach the affected system from the internet.