CVE-2017-4948

VMware Workstation (14.x before 14.1.0 and 12.x) and Horizon View Client (4.x before 4.7.0) contain an out-of-bounds read vulnerability in TPView.dll. On Workstation, this issue in conjunction with other bugs may allow a guest to leak information from host or may allow for a Denial of Service on the Windows OS that runs Workstation. In the case of a Horizon View Client, this issue in conjunction with other bugs may allow a View desktop to leak information from host or may allow for a Denial of Service on the Windows OS that runs the Horizon View Client. Exploitation is only possible if virtual printing has been enabled. This feature is not enabled by default on Workstation but it is enabled by default on Horizon View.

Weakness

The product reads data past the end, or before the beginning, of the intended buffer.

Affected Software

Potential Mitigations

• 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.
• To reduce the likelihood of introducing an out-of-bounds read, ensure that you validate and ensure correct calculations for any length argument, buffer size calculation, or offset. Be especially careful of relying on a sentinel (i.e. special character such as NUL) in untrusted inputs.

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/540.html

References

• http://www.securityfocus.com/bid/102441
• http://www.securitytracker.com/id/1040108
• http://www.securitytracker.com/id/1040109
• http://www.securitytracker.com/id/1040136
• https://www.vmware.com/us/security/advisories/VMSA-2018-0003.html