Instituto Nacional de ciberseguridad. Sección Incibe
Instituto Nacional de Ciberseguridad. Sección INCIBE-CERT

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CVE-2015-8542

Severity CVSS v4.0:
Pending analysis
Type:
Unavailable / Other
Publication date:
15/12/2016
Last modified:
12/04/2025

Description

An issue was discovered in Open-Xchange Guard before 2.2.0-rev8. The "getprivkeybyid" API call is used to download a PGP Private Key for a specific user after providing authentication credentials. Clients provide the "id" and "cid" parameter to specify the current user by its user- and context-ID. The "auth" parameter contains a hashed password string which gets created by the client by asking the user to enter his or her OX Guard password. This parameter is used as single point of authentication when accessing PGP Private Keys. In case a user has set the same password as another user, it is possible to download another user's PGP Private Key by iterating the "id" and "cid" parameters. This kind of attack would also be able by brute-forcing login credentials, but since the "id" and "cid" parameters are sequential they are much easier to predict than a user's login name. At the same time, there are some obvious insecure standard passwords that are widely used. A attacker could send the hashed representation of typically weak passwords and randomly fetch Private Key of matching accounts. The attack can be executed by both internal users and "guests" which use the external mail reader.

Impact

Vector 3.x
CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H CVSS v3.1 Severity and Metrics:

Base Score: 8.80 HIGH
Vector: CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Attack Vector (AV): Network
Attack Complexity (AC): Low
Privileges Required (PR): Low
User Interaction (UI): None
Scope (S): Unchanged
Confidentiality (C): High
Integrity (I): High
Availability (A): High

Base Score 3.x
8.80
Severity 3.x
HIGH
Vector 2.0
AV:N/AC:L/Au:S/C:P/I:N/A:N CVSS v2.0 Severity and Metrics:

Base Score: 4.00 MEDIUM
Vector: AV:N/AC:L/Au:S/C:P/I:N/A:N

Attack Vector (AV): Network
Attack Complexity (AC): Low
Authentication (Au): Single
Confidentiality (C): Physical
Integrity (I): None
Availability (A): None

Base Score 2.0
4.00
Severity 2.0
MEDIUM

Vulnerable products and versions

CPE From Up to
cpe:2.3:a:open-xchange:ox_guard:*:*:*:*:*:*:*:* 2.2.0 (including)

To consult the complete list of CPE names with products and versions, see this page


References to Advisories, Solutions, and Tools