Path Traversal in Apache Software Foundation Http Server
CVE-2021-41773
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…
Vulnerability class: Path Traversal (Directory Traversal)
EPSS: 0.944 (100.0th percentile) — read the EPSS interpretation.
Affected products
- Apache Software Foundation Http Server — versions Apache HTTP Server 2.4 2.4.49
Weakness classification (CWE)
CISA KEV (Known Exploited Vulnerabilities)
This CVE is on the CISA KEV catalog, added on . CISA KEV inclusion means CISA has confirmed in-the-wild exploitation; US federal agencies are required to remediate within a published due date.
BOD 22-01 due date: .
Required action: Apply updates per vendor instructions.
Known ransomware campaign use: yes.
Public proof-of-concept exploits
References
- httpd.apache.org/security/vulnerabilities_24.html (x_refsource_MISC)
- [httpd-users] 20211005 [users@httpd] CVE-2021-41773: Path traversal and file disclosure vulnerability in Apache HTTP Server 2.4.49 (mailing-list, x_refsource_MLIST)
- [announce] 20211005 CVE-2021-41773: Path traversal and file disclosure vulnerability in Apache HTTP Server 2.4.49 (mailing-list, x_refsource_MLIST)
- [oss-security] 20211005 CVE-2021-41773: Path traversal and file disclosure vulnerability in Apache HTTP Server 2.4.49 (mailing-list, x_refsource_MLIST)
- [oss-security] 20211007 RE: CVE-2021-41773: Path traversal and file disclosure vulnerability in Apache HTTP Server 2.4.49 (mailing-list, x_refsource_MLIST)
- [announce] 20211007 CVE-2021-42013: Path Traversal and Remote Code Execution in Apache HTTP Server 2.4.49 and 2.4.50 (incomplete fix of CVE-2021-41773) (mailing-list, x_refsource_MLIST)
- [httpd-users] 20211007 [users@httpd] CVE-2021-42013: Path Traversal and Remote Code Execution in Apache HTTP Server 2.4.49 and 2.4.50 (incomplete fix of CVE-2021-41773) (mailing-list, x_refsource_MLIST)
- [oss-security] 20211007 CVE-2021-42013: Path Traversal and Remote Code Execution in Apache HTTP Server 2.4.49 and 2.4.50 (incomplete fix of CVE-2021-41773) (mailing-list, x_refsource_MLIST)
- 20211007 Apache HTTP Server Vulnerabilties: October 2021 (vendor-advisory, x_refsource_CISCO)
- [oss-security] 20211008 Re: CVE-2021-42013: Path Traversal and Remote Code Execution in Apache HTTP Server 2.4.49 and 2.4.50 (incomplete fix of CVE-2021-41773) (mailing-list, x_refsource_MLIST)
Frequently asked questions
- What is CVE-2021-41773?
- CVE-2021-41773 is a vulnerability in Apache Software Foundation Http Server, classified under Path Traversal. Published 2021-10-05.
- Is CVE-2021-41773 known to be exploited?
- Yes. CVE-2021-41773 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2021-11-03), indicating it is being actively exploited. 606 public proof-of-concept repositories are indexed.