CVE Vulnerabilities

CVE-2019-4094

Uncontrolled Search Path Element

Published: Mar 21, 2019 | Modified: Jan 30, 2023
CVSS 3.x
7.8
HIGH
Source:
NVD
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CVSS 2.x
7.2 HIGH
AV:L/AC:L/Au:N/C:C/I:C/A:C
RedHat/V2
RedHat/V3
Ubuntu

IBM DB2 for Linux, UNIX and Windows (includes DB2 Connect Server) 9.7, 10.1, 10.5, and 11.1 binaries load shared libraries from an untrusted path potentially giving low privilege user full access to root by loading a malicious shared library. IBM X-Force ID: 158014.

Weakness

The product uses a fixed or controlled search path to find resources, but one or more locations in that path can be under the control of unintended actors.

Affected Software

Name Vendor Start Version End Version
Db2 Ibm 9.7 (including) 9.7 (including)
Db2 Ibm 10.1 (including) 10.1 (including)
Db2 Ibm 10.5 (including) 10.5 (including)
Db2 Ibm 11.1 (including) 11.1 (including)

Extended Description

Although this weakness can occur with any type of resource, it is frequently introduced when a product uses a directory search path to find executables or code libraries, but the path contains a directory that can be modified by an attacker, such as “/tmp” or the current working directory. In Windows-based systems, when the LoadLibrary or LoadLibraryEx function is called with a DLL name that does not contain a fully qualified path, the function follows a search order that includes two path elements that might be uncontrolled:

In some cases, the attack can be conducted remotely, such as when SMB or WebDAV network shares are used. One or more locations in that path could include the Windows drive root or its subdirectories. This often exists in Linux-based code assuming the controlled nature of the root directory (/) or its subdirectories (/etc, etc), or a code that recursively accesses the parent directory. In Windows, the drive root and some of its subdirectories have weak permissions by default, which makes them uncontrolled. In some Unix-based systems, a PATH might be created that contains an empty element, e.g. by splicing an empty variable into the PATH. This empty element can be interpreted as equivalent to the current working directory, which might be an untrusted search element. In software package management frameworks (e.g., npm, RubyGems, or PyPi), the framework may identify dependencies on third-party libraries or other packages, then consult a repository that contains the desired package. The framework may search a public repository before a private repository. This could be exploited by attackers by placing a malicious package in the public repository that has the same name as a package from the private repository. The search path might not be directly under control of the developer relying on the framework, but this search order effectively contains an untrusted element.

Potential Mitigations

References