Skip to content
Log inStart free trial

GHSA-m6ch-gg5f-wxx3 CVE-2016-5385

HTTP Proxy header vulnerability

High Packagist
Severity
8.1 / 10
High · CVSS 3.1
Exploit chance (EPSS)
50.43%
Chance of exploitation in the next 30 days. Higher than 98.91% of scored vulnerabilities.
Known exploited
No
Not in CISA's catalog
Weakness
CWE-601 URL Redirection to Untrusted Site ('Open Redirect')
Fix
Available
5 packages have a fixed version

Description

PHP through 7.0.8 does not attempt to address RFC 3875 section 4.1.18 namespace conflicts and therefore does not protect applications from the presence of untrusted client data in the HTTP_PROXY environment variable, which might allow remote attackers to redirect an application's outbound HTTP traffic to an arbitrary proxy server via a crafted Proxy header in an HTTP request, as demonstrated by (1) an application that makes a getenv('HTTP_PROXY') call or (2) a CGI configuration of PHP, aka an "httpoxy" issue.

Affected versions

Packagist

PackageVulnerableFixed in
amphp/artax
< 1.0.4
1.0.4
amphp/artax
>= 2.0.0, < 2.0.4
2.0.4
bugsnag/bugsnag-laravel
< 2.0.2
2.0.2
drupal/core
>= 8.0, < 8.1.7
8.1.7
guzzlehttp/guzzle
>= 6, < 6.2.1
6.2.1
guzzlehttp/guzzle
>= 4.0.0-rc2, < 4.2.4
4.2.4
guzzlehttp/guzzle
>= 5, < 5.3.1
5.3.1
padraic/humbug_get_contents
< 1.1.2
1.1.2

How to fix

Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.

amphp/artax Packagist → 1.0.4

composer
composer require amphp/artax:^1.0.4

bugsnag/bugsnag-laravel Packagist → 2.0.2

composer
composer require bugsnag/bugsnag-laravel:^2.0.2

drupal/core Packagist → 8.1.7

composer
composer require drupal/core:^8.1.7

guzzlehttp/guzzle Packagist → 6.2.1

composer
composer require guzzlehttp/guzzle:^6.2.1

padraic/humbug_get_contents Packagist → 1.1.2

composer
composer require padraic/humbug_get_contents:^1.1.2

Severity breakdown

CVSS 3.1 8.1

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

Attack vector
Network
Attack complexity
High
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

Weakness

CWE-601: URL Redirection to Untrusted Site ('Open Redirect')

The web application accepts a user-controlled input that specifies a link to an external site, and uses that link in a redirect.

How to prevent it
  • Implementation: Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does. When performing input validation, consider all potentially relevant properties, including length, type of input, the full range of acceptable values, missing or extra inputs, syntax, consistency across related fields, and conformance to business rules. As an example of business rule logic, "boat" may be syntactically valid because it only contains alphanumeric characters, but it is not valid if the input is only expected to contain colors such as "red" or "blue." Do not rely exclusively on looking for malicious or malformed inputs. This is likely to miss at least one undesirable input, especially if the code's environment changes. This can give attackers enough room to bypass the intended validation. However, denylists can be useful for detecting potential attacks or determining which inputs are so malformed that they should be rejected outright. Use a list of approved URLs or domains to be used for redirection.
  • Architecture and Design: Use an intermediate disclaimer page that provides the user with a clear warning that they are leaving the current site. Implement a long timeout before the redirect occurs, or force the user to click on the link. Be careful to avoid XSS problems (CWE-79) when generating the disclaimer page.
  • Architecture and Design: When the set of acceptable objects, such as filenames or URLs, is limited or known, create a mapping from a set of fixed input values (such as numeric IDs) to the actual filenames or URLs, and reject all other inputs. For example, ID 1 could map to "/login.asp" and ID 2 could map to "http://www.example.com/". Features such as the ESAPI AccessReferenceMap [REF-45] provide this capability.
  • Architecture and Design: Ensure that no externally-supplied requests are honored by requiring that all redirect requests include a unique nonce generated by the application [REF-483]. Be sure that the nonce is not predictable (CWE-330).
  • Architecture and Design, Implementation: Understand all the potential areas where untrusted inputs can enter your software: parameters or arguments, cookies, anything read from the network, environment variables, reverse DNS lookups, query results, request headers, URL components, e-mail, files, filenames, databases, and any external systems that provide data to the application. Remember that such inputs may be obtained indirectly through API calls. Many open redirect problems occur because the programmer assumed that certain inputs could not be modified, such as cookies and hidden form fields.
  • Operation: Use an application firewall that can detect attacks against this weakness. It can be beneficial in cases in which the code cannot be fixed (because it is controlled by a third party), as an emergency prevention measure while more comprehensive software assurance measures are applied, or to provide defense in depth [REF-1481].

References

Advisories

Other links

Timeline

  1. Published
  2. Last updated by the source
  3. Latest EPSS score
AdvisorySeverityWhy it's related
DRUPAL-CORE-2026-004
Drupal Core has a SQL Injection issue
Critical Known exploited Also affects drupal/core
CVE-2020-28949
Multiple vulnerabilities through filename manipulation in Archive_Tar
High Known exploited Also affects drupal/core
CVE-2020-13671
Drupal core Unrestricted Upload of File with Dangerous Type
High Known exploited Also affects drupal/core
CVE-2019-6340
Drupal Core Remote Code Execution Vulnerability
High Known exploited Also affects drupal/core
CVE-2018-7602
Drupal Core Remote Code Execution Vulnerability
Critical Known exploited Also affects drupal/core
CVE-2018-7600
Drupal Core Remote Code Execution Vulnerability
Critical Known exploited Also affects drupal/core
DRUPAL-CORE-2026-016
The Navigation module doesn't sufficiently sanitize certain attributes, which can lead to a cross-site scripting (XSS) vulnerability.
Not rated yet Also affects drupal/core
DRUPAL-CORE-2026-015
The Drupal core Link module provides a field type that can be used for internal and external URLs.
Not rated yet Also affects drupal/core
Is this in your code?

MergeHarbor checks every repository's dependencies against this database, ranks what matters by exploitability and reachability, routes it to the owning team and opens the fix pull request.

Check your repos with MergeHarbor