CVE-2001-0877Windows 98 Vulnerability
Universal Plug and Play (UPnP) on Windows 98, 98SE, ME, and XP allows remote attackers to cause a denial of service via (1) a spoofed SSDP advertisement that causes the client to connect to a service on another machine that generates a large amount of traffic (e.g., chargen), or…
Published Dec 20, 2001 · Updated Apr 15, 2026
Key Facts
Patch immediately- CVE-2001-0877 is a medium-severity vulnerability (CVSS 5.0 v2) affecting Windows 98 (Microsoft), Windows 98se (Microsoft), Windows Me (Microsoft) and 1 more product.
- It is exploited in the wild, listed in Industry KEV feed since Apr 26, 2016. No public exploit code is known.
- EPSS estimates a 44% probability of exploitation in the next 30 days.
- No fixed version is listed yet; check the vendor advisory for mitigations.
- Brandefense priority: patch immediately, because it is listed as exploited in the wild.
Scores
CVSS v2
5.0
AV:N/AC:L/Au:N/C:N/I:N/A:P
EPSS (30-day exploit likelihood)
44%
Higher than 98.7% of all scored CVEs
Exploit maturity
Exploited (KEV)
ATLAS score
46/100
Publication score, see How it works
Exploitation Verdict
KEV listed
Apr 26, 2016
5241 days after publication
Federal due date
None
No federal due date
Ransomware use
Not reported
Attributed actors
None named
Exploit & Defence Guidance
Exploit maturity
Exploited (KEV)
Public exploit code
0
Proof-of-concept links
In-the-wild evidence
1
Reports of active use
Advisories And Exploit References
- advisory20020109 UPNP Denial of Service
- patchCA-2001-37
Description
Universal Plug and Play (UPnP) on Windows 98, 98SE, ME, and XP allows remote attackers to cause a denial of service via (1) a spoofed SSDP advertisement that causes the client to connect to a service on another machine that generates a large amount of traffic (e.g., chargen), or (2) via a spoofed SSDP announcement to broadcast or multicast addresses, which could cause all UPnP clients to send traffic to a single target system.
Known-Exploited Catalog Listings
| Catalog | Added | Remediation due | Ransomware use |
|---|---|---|---|
| Industry KEV feed | Apr 26, 2016 | n/a | Not reported |
Affected Products
4 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| Windows 98Microsoft | See advisory | n/a |
| Windows 98seMicrosoft | See advisory | n/a |
| Windows MeMicrosoft | See advisory | n/a |
| Windows XpMicrosoft | See advisory | n/a |
Timeline
Publicly disclosed
Dec 20, 2001
Added to Industry KEV feed
Apr 26, 2016
Last updated
Apr 15, 2026
References
- advisory20020109 UPNP Denial of Service
- patchCA-2001-37
- exploitVulnCheck exploitation report
- other20011220 Multiple Remote Windows XP/ME/98 Vulnerabilities
- other20011220 Multiple Remote Windows XP/ME/98 Vulnerabilities
FAQ
Common Questions.
Universal Plug and Play (UPnP) on Windows 98, 98SE, ME, and XP allows remote attackers to cause a denial of service via (1) a spoofed SSDP advertisement that causes the client to connect to a service on another machine that generates a large amount of traffic (e.g., chargen), or (2) via a spoofed SSDP announcement to…
Affected: Windows 98 (Microsoft); Windows 98se (Microsoft); Windows Me (Microsoft), among others. The full list is in the CVE brief.
It is exploited in the wild, listed in Industry KEV feed since Apr 26, 2016.
No, it is not currently listed in the CISA Known Exploited Vulnerabilities catalog.
No public exploit code is known.
No fixed version is listed yet; check the vendor advisory for mitigations.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.
Is CVE-2001-0877 On Your Attack Surface?
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