CVE Vulnerabilities

CVE-2018-0409

Out-of-bounds Read

Published: Aug 15, 2018 | Modified: Aug 31, 2020
CVSS 3.x
7.5
HIGH
Source:
NVD
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS 2.x
5 MEDIUM
AV:N/AC:L/Au:N/C:N/I:N/A:P
RedHat/V2
RedHat/V3
Ubuntu

A vulnerability in the XCP Router service of the Cisco Unified Communications Manager IM & Presence Service (CUCM IM&P) and the Cisco TelePresence Video Communication Server (VCS) and Expressway could allow an unauthenticated, remote attacker to cause a temporary service outage for all IM&P users, resulting in a denial of service (DoS) condition. The vulnerability is due to improper validation of user-supplied input. An attacker could exploit this vulnerability by sending a malicious IPv4 or IPv6 packet to an affected device on TCP port 7400. An exploit could allow the attacker to overread a buffer, resulting in a crash and restart of the XCP Router service. Cisco Bug IDs: CSCvg97663, CSCvi55947.

Weakness

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

Affected Software

Name Vendor Start Version End Version
Telepresence_video_communication_server Cisco x8.7 x8.7
Telepresence_video_communication_server Cisco x8.9 x8.9
Telepresence_video_communication_server Cisco x7.0.1 x7.0.1
Telepresence_video_communication_server Cisco x8.2.2 x8.2.2
Telepresence_video_communication_server Cisco x8.8 x8.8
Telepresence_video_communication_server Cisco x7.2.4 x7.2.4
Telepresence_video_communication_server Cisco x8.1 x8.1
Telepresence_video_communication_server Cisco x8.10 x8.10
Telepresence_video_communication_server Cisco x8.10.4 x8.10.4
Telepresence_video_communication_server Cisco x8.5 x8.5
Telepresence_video_communication_server Cisco x8.6 x8.6

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.

References