Cross-origin content spoofing via Content-Length overflow
Published Jan 21, 2020 · Updated Aug 6, 2024
Integer overflow in Firefox 1.5.0.3 and earlier allows remote attackers to spoof cross-origin content via an oversized HTTP response. Firefox parses an excessive Content-Length value with PR_sscanf into a signed 64-bit length, allowing wraparound so leftover response bytes are treated as the next response. Exploitation requires persistent HTTP requests through a keep-alive proxy or different origins sharing an IP address and can present attacker-controlled forms or expose cookies.
Summary
What happened
Integer overflow in Firefox 1.5.0.3 and earlier allows remote attackers to spoof cross-origin content via an oversized HTTP response. Firefox parses an excessive Content-Length value with PR_sscanf into a signed 64-bit length, allowing wraparound so leftover response bytes are treated as the next response. Exploitation requires persistent HTTP requests through a keep-alive proxy or different origins sharing an IP address and can present attacker-controlled forms or expose cookies.
The record
- CVE
- CVE-2011-2668
- Published
- Jan 21, 2020
- Updated
- Aug 6, 2024
- Vendor
- Mozilla
- Product
- Firefox
- Classifications
- Unavailable
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jan 21, 2020CVE publishedPublication date reported by the CVE source.
- Aug 6, 2024Record 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=1.5.0.3 and earlier
What conditions does exploitation require?
What is affected?
Published CVSS scores
No CVSS assessment is available in this record.
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.
Weakness, pattern, technique
No sourced classifications are available.
Public exploit references
- Mozilla Bugzilla Python Content-Length testcaseproof 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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