CVE-2018-17972 - Improper Privilege Management

Severity

49%

Complexity

39%

Confidentiality

115%

An issue was discovered in the proc_pid_stack function in fs/proc/base.c in the Linux kernel through 4.18.11. It does not ensure that only root may inspect the kernel stack of an arbitrary task, allowing a local attacker to exploit racy stack unwinding and leak kernel task stack contents.

An issue was discovered in the proc_pid_stack function in fs/proc/base.c in the Linux kernel through 4.18.11. It does not ensure that only root may inspect the kernel stack of an arbitrary task, allowing a local attacker to exploit racy stack unwinding and leak kernel task stack contents.

CVSS 3.0 Base Score 5.5. CVSS Attack Vector: local. CVSS Attack Complexity: low. CVSS Vector: (CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N).

CVSS 2.0 Base Score 4.9. CVSS Attack Vector: local. CVSS Attack Complexity: low. CVSS Vector: (AV:L/AC:L/Au:N/C:C/I:N/A:N).

Demo Examples

Improper Privilege Management

CWE-269

This code temporarily raises the program's privileges to allow creation of a new user folder.


               
return True
return False#avoid CWE-22 and CWE-78
lowerPrivileges()
return False

While the program only raises its privilege level to create the folder and immediately lowers it again, if the call to os.mkdir() throws an exception, the call to lowerPrivileges() will not occur. As a result, the program is indefinitely operating in a raised privilege state, possibly allowing further exploitation to occur.

Improper Privilege Management

CWE-269

Evidence of privilege change:


               
seteuid(getuid());/* do some stuff */

               
}
// privileged code goes here, for example:// nothing to return

Improper Privilege Management

CWE-269

This code intends to allow only Administrators to print debug information about a system.


               
}
ADMIN,USER,GUEST
}
}
break;
break;
System.out.println("You must be logged in to perform this command");

While the intention was to only allow Administrators to print the debug information, the code as written only excludes those the with the role of "GUEST". Someone with the role of "ADMIN" or "USER" will be allowed access, which goes against the original intent. An attacker may be able to use this debug information to craft an attack on the system.

Improper Privilege Management

CWE-269

This code allows someone with the role of "ADMIN" or "OPERATOR" to reset a user's password. The role of "OPERATOR" is intended to have less privileges than an "ADMIN", but still be able to help users with small issues such as forgotten passwords.


               
}
ADMIN,OPERATOR,USER,GUEST
}
}
}
break;
break;
break;
System.out.println("You must be logged in to perform this command");

This code does not check the role of the user whose password is being reset. It is possible for an Operator to gain Admin privileges by resetting the password of an Admin account and taking control of that account.

Overview

First reported 6 years ago

2018-10-03 22:29:00

Last updated 5 years ago

2019-10-03 00:03:00

Affected Software

Linux Kernel

Canonical Ubuntu Linux 12.04 ESM (Extended Security Maintenance)

12.04

Canonical Ubuntu Linux 14.04 LTS (Long-Term Support)

14.04

Canonical Ubuntu Linux 16.04 LTS (Long-Term Support)

16.04

Canonical Ubuntu Linux 18.04 LTS Edition

18.04

Canonical Ubuntu Linux 18.10

18.10

RedHat Enterprise Linux Desktop 7.0

7.0

RedHat Enterprise Linux Server 7.0

7.0

Red Hat Enterprise Linux Server 7.6

7.6

Red Hat Enterprise Linux Server Advanced mission critical Update Support (AUS) 7.6

7.6

Red Hat Enterprise Linux Server Extended Update Support (EUS) 7.6

7.6

Red Hat Enterprise Linux Server Telecommunications Update Service (TUS) 7.6

7.6

RedHat Enterprise Linux Workstation 7.0

7.0

Red Hat Virtualization 4.0

4.0

Debian Linux 8.0 (Jessie)

8.0

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