The ngx_http_parse_chunked function in http/ngx_http_parse.c in nginx 1.3.9 through 1.4.0 allows remote attackers to cause a denial of service (crash) and execute arbitrary code via a chunked Transfer-Encoding request with a large chunk size, which triggers an integer signedness error and a stack-based buffer overflow.

According to its Server response header, the installed version of nginx is greater than or equal to 1.1.4 and prior to 1.2.9, or greater than or equal to 1.3.0 and prior to 1.4.1. It is, therefore, affected by multiple vulnerabilities :

 - A stack-based buffer overflow in 'ngx_http_parse.c' may allow a remote attacker to execute arbitrary code or trigger a denial of service condition via a specially crafted HTTP request. This vulnerability only affects versions greater than or equal to 1.3.9 and less than 1.4.1. (CVE-2013-2028)

 - A memory disclosure vulnerability in 'ngx_http_parse.c' affects servers that use 'proxy_pass' to untrusted upstream servers. This issue can be triggered by a remote attacker via a specially crafted HTTP request. Failed attempts may result in a denial of service condition. (CVE-2013-2070)

Note that the scanner has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote host is affected by the vulnerability described in GLSA-201310-04 (nginx: Multiple vulnerabilities)

    Multiple vulnerabilities have been discovered in nginx. Please review       the CVE identifiers referenced below for details.
  Impact :

    A remote attacker could send a specially crafted request, possibly       resulting in execution of arbitrary code with the privileges of the       process, or a Denial of Service condition. Furthermore, a       context-dependent attacker may be able to obtain sensitive information.
  Workaround :

    There is no known workaround at this time.

According to its Server response header, the installed version of nginx is 1.1.4 through 1.2.8, 1.3.x, or 1.4.x prior to 1.4.1.  It is, therefore, affected by multiple vulnerabilities :

  - A stack-based buffer overflow in 'ngx_http_parse.c' may     allow a remote attacker to execute arbitrary code or     trigger a denial of service condition via a specially     crafted HTTP request. This vulnerability only affects     versions greater than or equal to 1.3.9 and less than     1.4.1. (CVE-2013-2028)

  - A memory disclosure vulnerability in 'ngx_http_parse.c'     affects servers that use 'proxy_pass' to untrusted     upstream servers.  This issue can be triggered by a     remote attacker via a specially crafted HTTP request.
    Failed attempts may result in a denial of service     condition. (CVE-2013-2070)

Update to upstream release 1.4.1 which fixes :

  - CVE-2013-2028: Stack-based buffer overflow when handling     certain chunked transfer encoding requests

Note that Tenable Network Security has extracted the preceding description block directly from the Fedora security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

Older versions of nginx are affected by the following vulnerabilities:

  - Older versions using proxy_pass can cause denial of service or disclosure of worker process memory. Failed exploit attempts will result in a denial-of-service condition. (CVE-2013-2070)

  - A related vulnerability in nginx versions 1.3.9-1.4.0 is a stack-based buffer-overflow vulnerability, due to an error in the 'ngx_http_parse.c' source file. Specifically, this issue occurs in a worker process when handling a specially crafted request. Successfully exploiting this issue allows attackers to execute arbitrary code in the context of the vulnerable application (CVE-2013-2028).

The nginx project reports :

A stack-based buffer overflow might occur in a worker process process while handling a specially crafted request, potentially resulting in arbitrary code execution. [CVE-2013-2028]

A security problem related to CVE-2013-2028 was identified, affecting some previous nginx versions if proxy_pass to untrusted upstream HTTP servers is used.

The problem may lead to a denial of service or a disclosure of a worker process memory on a specially crafted response from an upstream proxied server. [CVE-2013-2070]

ID	Name	Product	Family	Severity
98951	Nginx < 1.2.9 ngx_http_proxy_module.c Multiple Vulnerabilities	Web App Scanning	Component Vulnerability	critical
98950	Nginx < 1.4.1 ngx_http_proxy_module.c Multiple Vulnerabilities	Web App Scanning	Component Vulnerability	critical
70310	GLSA-201310-04 : nginx: Multiple vulnerabilities	Nessus	Gentoo Local Security Checks	high
66672	nginx ngx_http_proxy_module.c Multiple Vulnerabilities	Nessus	Web Servers	critical
66387	Fedora 19 : nginx-1.4.1-1.fc19 (2013-7560)	Nessus	Fedora Local Security Checks	high
6795	nginx < 1.4.1 / 1.5.0 Multiple Vulnerabilities	Nessus Network Monitor	Web Servers	high
66341	FreeBSD : nginx -- multiple vulnerabilities (efaa4071-b700-11e2-b1b9-f0def16c5c1b)	Nessus	FreeBSD Local Security Checks	high

Detections

Analytics

CVE-2013-2028

critical

Tenable Plugins

critical

critical

high

critical

high

high

high