Out-of-bounds write via truncated percent escape
Published Aug 5, 2022 · Updated Apr 15, 2025
Out-of-bounds write in DD-WRT httpd revisions 32270 through 48599 allows remote attackers to corrupt memory via a crafted HTTP request. The unescape function assumes every percent sign has two following hex characters, then shifts bytes with strncpy from beyond a truncated escape. No authentication or user interaction is required; the published analysis demonstrates malformed buffer contents but does not establish code execution, disclosure, or service interruption.
Summary
What happened
Out-of-bounds write in DD-WRT httpd revisions 32270 through 48599 allows remote attackers to corrupt memory via a crafted HTTP request. The unescape function assumes every percent sign has two following hex characters, then shifts bytes with strncpy from beyond a truncated escape. No authentication or user interaction is required; the published analysis demonstrates malformed buffer contents but does not establish code execution, disclosure, or service interruption.
The record
- CVE
- CVE-2022-27631
- Published
- Aug 5, 2022
- Updated
- Apr 15, 2025
- Vendor
- DD-WRT
- Product
- DD-WRT
- Classifications
- CWE-787, T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Aug 5, 2022CVE publishedPublication date reported by the CVE source.
- Apr 15, 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?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=Revision 32270 - Revision 48599
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Public exploit references
- Cisco Talos unescape demonstrationproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
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Your stack
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