CVE-2016-5387
Description
It was discovered that httpd used the value of the Proxy header from HTTP requests to initialize the HTTP_PROXY environment variable for CGI scripts, which in turn was incorrectly used by certain HTTP client implementations to configure the proxy for outgoing HTTP requests. A remote attacker could possibly use this flaw to redirect HTTP requests performed by a CGI script to an attacker-controlled proxy via a malicious HTTP request.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 5 | 8.1 | N/A |
| Attack Vector | Network | Network | N/A |
| Attack Complexity | Low | High | N/A |
| Privileges Required | Low | None | N/A |
| User Interaction | None | None | N/A |
| Scope | Changed | Unchanged | N/A |
| Confidentiality | None | High | N/A |
| Integrity Impact | Low | High | N/A |
| Availability Impact | None | High | N/A |
Vector
Red Hat: CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:L/A:N
NVD: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS v2 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 5 | 6.8 | N/A |
| Attack Vector | Network | Network | N/A |
| Access Complexity | Low | Medium | N/A |
| Authentication | None | None | N/A |
| Confidentiality Impact | None | Partial | N/A |
| Integrity Impact | Partial | Partial | N/A |
| Availability Impact | None | Partial | N/A |
Vector
Red Hat: AV:N/AC:L/Au:N/C:N/I:P/A:N
NVD: AV:N/AC:M/Au:N/C:P/I:P/A:P
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Crash, Exit, or Restart; DoS: Resource Consumption (CPU); DoS: Resource Consumption (Memory)
An attacker could provide unexpected values and cause a program crash or arbitrary control of resource allocation, leading to excessive consumption of resources such as memory and CPU.
Confidentiality
Technical Impact: Read Memory; Read Files or Directories
An attacker could read confidential data if they are able to control resource references.
Integrity,Confidentiality,Availability
Technical Impact: Modify Memory; Execute Unauthorized Code or Commands
An attacker could use malicious input to modify data or possibly alter control flow in unexpected ways, including arbitrary command execution.
Acknowledgements
Red Hat would like to thank Scott Geary (VendHQ) for reporting this issue.
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