CVE-2021-41773

Description

A flaw was found in a change made to path normalization in Apache HTTP Server 2.4.49. An attacker could use a path traversal attack to map URLs to files outside the directories configured by Alias-like directives. If files outside of these directories are not protected by the usual default configuration "require all denied", these requests can succeed. If CGI scripts are also enabled for these aliased pathes, this could allow for remote code execution. This issue is known to be exploited in the wild. This issue only affects Apache 2.4.49 and not earlier versions. The fix in Apache HTTP Server 2.4.50 was found to be incomplete, see CVE-2021-42013.

References

Vendor Advisory
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Mailing ListThird Party Advisory
ExploitThird Party AdvisoryVDB Entry
Third Party Advisory
ExploitThird Party Advisory
Mailing ListVendor Advisory
Mailing ListVendor Advisory
Third Party Advisory
Third Party Advisory
Third Party Advisory
Mailing ListVendor Advisory
Third Party Advisory
Third Party Advisory
Third Party Advisory
Third Party Advisory
Third Party Advisory
Third Party Advisory
Third Party Advisory

CvssV3 impact

BaseSeverity

HIGH

ConfidentialityImpact

HIGH

AttackComplexity

LOW

Scope

UNCHANGED

AttackVector

NETWORK

AvailabilityImpact

NONE

IntegrityImpact

NONE

PrivilegesRequired

NONE

BaseScore

7.5

VectorString

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Version

3.1

UserInteraction

NONE

CvssV2 impact

AccessComplexity

MEDIUM

ConfidentialityImpact

PARTIAL

AvailabilityImpact

NONE

IntegrityImpact

NONE

BaseScore

4.3

VectorString

AV:N/AC:M/Au:N/C:P/I:N/A:N

Version

2.0

AccessVector

NETWORK

Authentication

NONE