CVE-2021-33318 json
Improper Input Validation in IpMatcher
published 2022-05-16 4 y ago modified 2026-06-17 4 mo ago also GHSA-qj93-37f5-mr29 , EUVD-2022-4989
- cvss
- 9.8
- version 3.1, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 2.1%
- EPSS 2.1% chance of exploitation in 30 days, percentile 81%
- public exploits
- 0
- none known
Summary
An Input Validation Vulnerability exists in Joel Christner .NET C# packages WatsonWebserver, IpMatcher 1.0.4.1 and below (IpMatcher) and 4.1.3 and below (WatsonWebserver) due to insufficient validation of input IP addresses and netmasks against the internal Matcher list of IP addresses and subnets.
Patch / fix
Exploit prediction
2.05% chance of exploitation in the next 30 days, higher than 81% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- github.com https://github.com/kaoudis/advisories/blob/main/0-2021.md referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| NVD | 3.1 | 9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| NVD | 2.0 | 7.5 | AV:N/AC:L/Au:N/C:P/I:P/A:P |
| GitHub | 3.1 | 9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| nuget | IpMatcher | <1.0.4.2 |
1.0.4.2 |
Classification
References
-
github.com
/jchristn/IpMatcher/commit/81d77c2f33aa912dbd032b34b9e184fc6e041d89
web, patch, third-party-advisory
-
github.com
/kaoudis/advisories/blob/main/0-2021.md
web, exploit, third-party-advisory
-
github.com
/jchristn/IpMatcher
package, third-party-advisory
-
github.com
/jchristn/WatsonWebserver
web, third-party-advisory
-
nvd.nist.gov
/vuln/detail/CVE-2021-33318
advisory
Sources
- CVE List CVE-2021-33318
- GitHub Advisory GHSA-qj93-37f5-mr29
- NVD CVE-2021-33318
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