CVE Vulnerabilities

CVE-2020-15634

Use of Externally-Controlled Format String

Published: Aug 20, 2020 | Modified: Aug 24, 2020
CVSS 3.x
6.3
MEDIUM
Source:
NVD
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
CVSS 2.x
5.8 MEDIUM
AV:A/AC:L/Au:N/C:P/I:P/A:P
RedHat/V2
RedHat/V3
Ubuntu

This vulnerability allows network-adjacent attackers to execute arbitrary code on affected installations of NETGEAR R6700 routers with firmware 1.0.4.84_10.0.58. Authentication is not required to exploit this vulnerability. The specific flaw exists within the handling of string table file uploads. The issue results from the lack of proper validation of a user-supplied string before using it as a format specifier. An attacker can leverage this vulnerability to execute code in the context of the web server. Was ZDI-CAN-9755.

Weakness

The product uses a function that accepts a format string as an argument, but the format string originates from an external source.

Affected Software

Name Vendor Start Version End Version
R6700_firmware Netgear * 1.0.4.98 (excluding)

Extended Description

When an attacker can modify an externally-controlled format string, this can lead to buffer overflows, denial of service, or data representation problems. It should be noted that in some circumstances, such as internationalization, the set of format strings is externally controlled by design. If the source of these format strings is trusted (e.g. only contained in library files that are only modifiable by the system administrator), then the external control might not itself pose a vulnerability.

Potential Mitigations

References