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CVE-2018-11574: Point To Point Protocol Project: Authentication bypass

CVE-2018-11574 is rated critical with a CVSS v3.1 base score of 9.8 and NVD lists 2 affected products, including Point To Point Protocol Project. Per its scoring, it can be exploited over the network, without authentication, without any user interaction. The scored impact on confidentiality, integrity and availability is the highest available.

Vulnerability description

Improper input validation together with an integer overflow in the EAP-TLS protocol implementation in PPPD may cause a crash, information disclosure, or authentication bypass. This implementation is distributed as a patch for PPPD 0.91, and includes the affected eap.c and eap-tls.c files. Configurations that use the `refuse-app` option are unaffected.

Severity breakdown

CVSS v3.1 9.8: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

  • Attack vector: Network. Exploitable remotely over the network, with no need for local or physical access.
  • Attack complexity: Low. No special conditions; the attack can be repeated reliably.
  • Privileges required: None. No account or prior access is needed.
  • User interaction: None. No action from any user is needed.
  • Scope: Unchanged. Impact stays within the vulnerable component.
  • Confidentiality impact: High. Total loss of confidentiality; sensitive data can be fully disclosed.
  • Integrity impact: High. Total loss of integrity; data or system state can be fully modified.
  • Availability impact: High. Total loss of availability; the component can be shut down.

Underlying weakness

CWE-20: Improper Input Validation

The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.

CWE-190: Integer Overflow or Wraparound

The product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number.

Affected products

  • Point To Point Protocol Project: before 2.4.9
  • Canonical Ubuntu Linux: 14.04; 16.04; 18.04

References