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CVE-2011-3639

MEDIUM · CVSS 4.3EPSS 49.7%EU EUVD

The mod_proxy module in the Apache HTTP Server 2.0.x through 2.0.64 and 2.2.x before 2.2.18, when the Revision 1179239 patch is in place, does not properly interact with use of (1) RewriteRule and (2) ProxyPassMatch pattern matches for configuration of a reverse proxy, which allows remote attackers to send requests to intranet servers by using the HTTP/0.9 protocol with a malformed URI containing an initial @ (at sign) character. NOTE: this vulnerability exists because of an incomplete fix for CVE-2011-3368.

Key facts

CVSS score
4.3 (v2.0)
Severity
MEDIUM
CVSS vector
AV:N/AC:M/Au:N/C:N/I:P/A:N
Weakness (CWE)
CWE-20
EPSS score
49.7% (99th percentile)
In CISA KEV
No
In EU EUVD
Yes (EUVD-2011-3598)
Published
November 30, 2011
NVD last modified
June 16, 2026
Status
Modified

EU Vulnerability Database (EUVD)

This vulnerability is also tracked by ENISA as EUVD-2011-3598 in the EU Vulnerability Database. Last updated in EUVD on August 6, 2024.

View on the EU Vulnerability Database

Affected products

  • apache / http server
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and 26 more…

References

Last updated September 17, 2026 · Source: NVD, CISA KEV, FIRST.org EPSS

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