Unauthenticated IOx service hang via crafted HTTP requests
Published May 7, 2025 · Updated May 7, 2025
Denial of service in Cisco IOx on Cisco IOS and IOS XE allows remote attackers to hang the hosting environment via crafted HTTP requests. The IOx HTTP request handler improperly processes crafted requests, leaving the IOx process unresponsive rather than rejecting them safely. IOx and HTTP Server must both be enabled—IOx is off by default—and recovery requires a manual IOx process restart.
Summary
What happened
Denial of service in Cisco IOx on Cisco IOS and IOS XE allows remote attackers to hang the hosting environment via crafted HTTP requests. The IOx HTTP request handler improperly processes crafted requests, leaving the IOx process unresponsive rather than rejecting them safely. IOx and HTTP Server must both be enabled—IOx is off by default—and recovery requires a manual IOx process restart.
The record
- CVE
- CVE-2025-20196
- Published
- May 7, 2025
- Updated
- May 7, 2025
- Vendor
- ClamAV
- Product
- Cisco IOS
- Classifications
- CWE-307, T1499
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- May 7, 2025CVE publishedPublication date reported by the CVE source.
- May 7, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
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- Affected versionversion=N/A
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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