Summary
Package updates are available for Amazon Linux 2 that fix the following vulnerabilities: CVE-2021-42013: A path transversal and remote code execution flaw was found in Apache HTTP Server 2.4.49 and 2.4.50. A remote attacker could use this flaw to map URLs to files outside the expected document root. Additionally, this flaw could leak the source of interpreted files like CGI scripts. 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 paths, this could allow for remote code execution. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability. This is an incomplete fix for CVE-2021-41773. 2011900: CVE-2021-42013 httpd: path traversal and remote code execution (incomplete fix of CVE-2021-41773) CVE-2021-41773: A path transversal flaw was found in Apache 2.4.49. A remote attacker could use this flaw to map URLs to files outside the expected document root. Additionally this flaw could leak the source of interpreted files like CGI scripts. 2010757: CVE-2021-41773 httpd: path traversal and file disclosure vulnerability CVE-2021-41524: While fuzzing the 2.4.49 httpd, a new null pointer dereference was detected during HTTP/2 request processing, allowing an external source to DoS the server. This requires a specially crafted request. The vulnerability was recently introduced in version 2.4.49. No exploit is known to the project. 2010934: CVE-2021-41524 httpd: NULL pointer dereference via crafted request during HTTP/2 request processing CVE-2021-40438: A Server-Side Request Forgery (SSRF) flaw was found in mod_proxy of httpd. This flaw allows a remote, unauthenticated attacker to make the httpd server forward requests to an arbitrary server. The attacker could get, modify, or delete resources on other services that may be behind a firewall and inaccessible otherwise. The impact of this flaw varies based on what services and resources are available on the httpd network. 2005117: CVE-2021-40438 httpd: mod_proxy: SSRF via a crafted request uri-path containing "unix:" CVE-2021-39275: An out-of-bounds write in function ap_escape_quotes of httpd allows an unauthenticated remote attacker to crash the server or potentially execute code on the system with the privileges of the httpd user, by providing malicious input to the function. 2005119: CVE-2021-39275 httpd: out-of-bounds write in ap_escape_quotes() via malicious input CVE-2021-36160: An out-of-bounds read in mod_proxy_uwsgi of httpd allows a remote unauthenticated attacker to crash the service through a crafted request. The highest threat from this vulnerability is to system availability. 2005124: CVE-2021-36160 httpd: mod_proxy_uwsgi: out-of-bounds read via a crafted request uri-path CVE-2021-34798: A NULL pointer dereference in httpd allows an unauthenticated remote attacker to crash httpd by providing malformed HTTP requests. The highest threat from this vulnerability is to system availability. 2005128: CVE-2021-34798 httpd: NULL pointer dereference via malformed requests CVE-2021-33193: A NULL pointer dereference was found in Apache httpd mod_h2. The highest threat from this flaw is to system integrity. 1966728: CVE-2021-33193 httpd: Request splitting via HTTP/2 method injection and mod_proxy
Fixed packages 11
| Release | Package | Fixed in |
|---|---|---|
| Amazon Linux · 2 | httpd | 0:2.4.51-1.amzn2 |
| Amazon Linux · 2 | httpd-debuginfo | 0:2.4.51-1.amzn2 |
| Amazon Linux · 2 | httpd-devel | 0:2.4.51-1.amzn2 |
| Amazon Linux · 2 | httpd-filesystem | 0:2.4.51-1.amzn2 |
| Amazon Linux · 2 | httpd-manual | 0:2.4.51-1.amzn2 |
| Amazon Linux · 2 | httpd-tools | 0:2.4.51-1.amzn2 |
| Amazon Linux · 2 | mod_ldap | 0:2.4.51-1.amzn2 |
| Amazon Linux · 2 | mod_md | 0:2.4.51-1.amzn2 |
| Amazon Linux · 2 | mod_proxy_html | 1:2.4.51-1.amzn2 |
| Amazon Linux · 2 | mod_session | 0:2.4.51-1.amzn2 |
| Amazon Linux · 2 | mod_ssl | 1:2.4.51-1.amzn2 |
Vulnerabilities 8
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Critical 9.8
Path Traversal and Remote Code Execution in Apache HTTP Server 2.4.49 and 2.4.50 (incomplete fix of CVE-2021-41773)
It was found that the fix for CVE-2021-41773 in Apache HTTP Server 2.4.50 was insufficient. 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 a…
KEV Nov 3, 2021 -
Critical 9.0
mod_proxy SSRF
A crafted request uri-path can cause mod_proxy to forward the request to an origin server choosen by the remote user. This issue affects Apache HTTP Server 2.4.48 and earlier.
KEV Dec 1, 2021 -
High 7.5
Path traversal and file disclosure vulnerability in Apache HTTP Server 2.4.49
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…
KEV Nov 3, 2021 -
Unscored —CVE-2021-33193 EPSS 46%
Request splitting via HTTP/2 method injection and mod_proxy
A crafted method sent through HTTP/2 will bypass validation and be forwarded by mod_proxy, which can lead to request splitting or cache poisoning. This issue affects Apache HTTP Server 2.4.17 to 2.4.48.
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Unscored —CVE-2021-34798 EPSS 65%
NULL pointer dereference in httpd core
Malformed requests may cause the server to dereference a NULL pointer. This issue affects Apache HTTP Server 2.4.48 and earlier.
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Unscored —CVE-2021-36160 EPSS 64%
mod_proxy_uwsgi out of bound read
A carefully crafted request uri-path can cause mod_proxy_uwsgi to read above the allocated memory and crash (DoS). This issue affects Apache HTTP Server versions 2.4.30 to 2.4.48 (inclusive).
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Unscored —CVE-2021-39275 EPSS 39%
ap_escape_quotes buffer overflow
ap_escape_quotes() may write beyond the end of a buffer when given malicious input. No included modules pass untrusted data to these functions, but third-party / external modules may. This issue affects Apache HTTP Server 2.4.48 and earlier.
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Unscored —CVE-2021-41524 EPSS 26%
null pointer dereference in h2 fuzzing
While fuzzing the 2.4.49 httpd, a new null pointer dereference was detected during HTTP/2 request processing, allowing an external source to DoS the server. This requires a specially crafted request. The vulnerability was recently introduced in version 2.4.49…
References
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web
https://alas.aws.amazon.com/cve/html/CVE-2021-33193.html
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web
https://alas.aws.amazon.com/cve/html/CVE-2021-34798.html
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web
https://alas.aws.amazon.com/cve/html/CVE-2021-36160.html
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web
https://alas.aws.amazon.com/cve/html/CVE-2021-39275.html
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web
https://alas.aws.amazon.com/cve/html/CVE-2021-40438.html
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web
https://alas.aws.amazon.com/cve/html/CVE-2021-41524.html
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web
https://alas.aws.amazon.com/cve/html/CVE-2021-41773.html
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web
https://alas.aws.amazon.com/cve/html/CVE-2021-42013.html