CVE-2021-31359 - Improper Privilege Management

Severity

78%

Complexity

18%

Confidentiality

98%

A local privilege escalation vulnerability in Juniper Networks Junos OS and Junos OS Evolved allows a local, low-privileged user to cause the Juniper DHCP daemon (jdhcpd) process to crash, resulting in a Denial of Service (DoS), or execute arbitrary commands as root. Continued processing of malicious input will repeatedly crash the system and sustain the Denial of Service (DoS) condition. This issue affects: Juniper Networks Junos OS: All versions, including the following supported releases: 15.1 versions prior to 15.1R7-S10; 17.4 versions prior to 17.4R3-S5; 18.3 versions prior to 18.3R3-S5; 18.4 versions prior to 18.4R3-S9; 19.1 versions prior to 19.1R3-S6; 19.2 versions prior to 19.2R1-S7, 19.2R3-S3; 19.3 versions prior to 19.3R2-S6, 19.3R3-S3; 19.4 versions prior to 19.4R3-S6; 20.1 versions prior to 20.1R2-S2, 20.1R3-S1; 20.2 versions prior to 20.2R3-S2; 20.3 versions prior to 20.3R3; 20.4 versions prior to 20.4R2-S1, 20.4R3; 21.1 versions prior to 21.1R1-S1, 21.1R2. Juniper Networks Junos OS Evolved: All versions prior to 20.4R2-S3-EVO; All versions of 21.1-EVO.

A local privilege escalation vulnerability in Juniper Networks Junos OS and Junos OS Evolved allows a local, low-privileged user to cause the Juniper DHCP daemon (jdhcpd) process to crash, resulting in a Denial of Service (DoS), or execute arbitrary commands as root. Continued processing of malicious input will repeatedly crash the system and sustain the Denial of Service (DoS) condition. Systems are only vulnerable if jdhcpd is running, which can be confirmed via the 'show system processes' command. For example: root@host# run show system processes extensive | match dhcp 26537 root -16 0 97568K 13692K RUN 0 0:01 3.71% jdhcpd This issue affects: Juniper Networks Junos OS: All versions, including the following supported releases: 15.1 versions prior to 15.1R7-S10; 17.4 versions prior to 17.4R3-S5; 18.3 versions prior to 18.3R3-S5; 18.4 versions prior to 18.4R3-S9; 19.1 versions prior to 19.1R3-S6; 19.2 versions prior to 19.2R1-S7, 19.2R3-S3; 19.3 versions prior to 19.3R2-S6, 19.3R3-S3; 19.4 versions prior to 19.4R3-S6; 20.1 versions prior to 20.1R2-S2, 20.1R3-S1; 20.2 versions prior to 20.2R3-S2; 20.3 versions prior to 20.3R3; 20.4 versions prior to 20.4R2-S1, 20.4R3; 21.1 versions prior to 21.1R1-S1, 21.1R2. Juniper Networks Junos OS Evolved: All versions prior to 20.4R2-S3-EVO; All versions of 21.1-EVO.

CVSS 3.1 Base Score 7.8. CVSS Attack Vector: local. CVSS Attack Complexity: low. CVSS Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H).

CVSS 2.0 Base Score 7.2. CVSS Attack Vector: local. CVSS Attack Complexity: low. CVSS Vector: (AV:L/AC:L/Au:N/C:C/I:C/A:C).

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

Type

Juniper

First reported 3 years ago

2021-10-19 19:15:00

Last updated 3 years ago

2021-11-17 22:18:00

Affected Software

Juniper Junos OS 15.1

15.1

Juniper Junos 15.1 A1

15.1

Juniper JUNOS 15.1 F

15.1

Juniper JunOS 15.1 F1

15.1

Juniper JunOS 15.1 F2

15.1

Juniper JunOS 15.1 F2-s1

15.1

Juniper Junos 15.1 F2-S2

15.1

Juniper Junos 15.1 F2-S3

15.1

Juniper Junos 15.1 F2-S4

15.1

Juniper Junos 15.1 F3

15.1

Juniper Junos 15.1 F4

15.1

Juniper Junos 15.1 F5

15.1

Juniper Junos 15.1 F5-S7

15.1

Juniper JUNOS 15.1 F6

15.1

Juniper JUNOS 15.1 F6-s1

15.1

Juniper Junos OS 15.1 F6-s12

15.1

Juniper JUNOS 15.1 F6-s2

15.1

Juniper JUNOS 15.1 F6-S3

15.1

Juniper Junos 15.1 F6-S4

15.1

Juniper Junos 15.1 F6-S7

15.1

Juniper JunOS 15.1 F7

15.1

Juniper Junos 15.1 R1

15.1

Juniper JunOS 15.1 R2

15.1

Juniper Junos 15.1 R3

15.1

Juniper JunOS 15.1 R4

15.1

Juniper Junos 15.1 R4-S7

15.1

Juniper Junos 15.1 R4-S8

15.1

Juniper Junos 15.1 R4-S9

15.1

Juniper JunOS 15.1 R5

15.1

Juniper Junos 15.1 R5-S1

15.1

Juniper Junos 15.1 R5-S5

15.1

Juniper JUNOS 15.1 R5-S6

15.1

Juniper JunOS 15.1 R6

15.1

Juniper Junos 15.1 R6-S1

15.1

Juniper JUNOS 15.1 R6-S2

15.1

Juniper Junos 15.1 R6-S6

15.1

Juniper Junos OS 15.1 R7

15.1

Juniper JUNOS 15.1 R7-S1

15.1

Juniper JUNOS 15.1 R7-S2

15.1

Juniper JUNOS 15.1 R7-S3

15.1

Juniper Junos OS 15.1 R7-s4

15.1

Juniper Junos OS 15.1 R7-s5

15.1

Juniper JUNOS 17.4

17.4

Juniper Junos 17.4 R1

17.4

Juniper JUNOS 17.4 R1-S1

17.4

Juniper JUNOS 17.4 R1-S2

17.4

Juniper JUNOS 17.4R1-S4

17.4

Juniper JunOS 17.4 R1-s5

17.4

Juniper JUNOS 17.4 R1-S6

17.4

Juniper JUNOS 17.4R1-S7

17.4

Juniper Junos 17.4 R2

17.4

Juniper JUNOS 17.4 R2-S1

17.4

Juniper JUNOS 17.4 R2-S10

17.4

Juniper Junos 17.4 R2-S2

17.4

Juniper JUNOS 17.4 R2-S3

17.4

Juniper JUNOS 17.4R2-S4

17.4

Juniper JUNOS 17.4 R2-S5

17.4

Juniper JUNOS 17.4 R2-S6

17.4

Juniper JUNOS 17.4 R2-S7

17.4

Juniper JUNOS 17.4 R2-S8

17.4

Juniper JUNOS 17.4 R2-S9

17.4

Juniper JUNOS 17.4 R3

17.4

Juniper JUNOS 17.4 R3-S1

17.4

Juniper JUNOS 18.3

18.3

Juniper JUNOS 18.3 R1

18.3

Juniper JUNOS 18.3 R1-S1

18.3

Juniper JUNOS 18.3 R1-S2

18.3

Juniper JUNOS 18.3R1-S3

18.3

Juniper JUNOS 18.3 R1-S5

18.3

Juniper JUNOS 18.3 R1-S6

18.3

Juniper JUNOS 18.3 R2

18.3

Juniper JUNOS 18.3 R2-S1

18.3

Juniper JUNOS 18.3 R2-S2

18.3

Juniper JUNOS 18.3 R2-S3

18.3

Juniper JUNOS 18.3 R3

18.3

Juniper JUNOS 18.3 R3-S1

18.3

Juniper JUNOS 18.4

18.4

Juniper JunOS 18.4 R1

18.4

Juniper Junos OS 18.4 R1-S1

18.4

Juniper JUNOS 18.4R1-S2

18.4

Juniper JUNOS 18.4 R1-S5

18.4

Juniper JUNOS 18.4 R1-S6

18.4

Juniper JUNOS 18.4R2

18.4

Juniper JUNOS 18.4 R2-S1

18.4

Juniper JUNOS 18.4 R2-S2

18.4

Juniper JUNOS 18.4 R2-S3

18.4

Juniper JUNOS 18.4 R3

18.4

Juniper Junos OS 19.1

19.1

Juniper Junos OS 19.1 R1

19.1

Juniper Junos OS 19.1 R1-s1

19.1

Juniper JUNOS 19.1 R1-S2

19.1

Juniper JUNOS 19.1 R1-S3

19.1

Juniper JUNOS 19.1 R1-S4

19.1

Juniper Junos OS 19.1 R2

19.1

Juniper Junos OS 19.2

19.2

Juniper Junos OS 19.2 R1

19.2

Juniper JUNOS 19.2 R1-S1

19.2

Juniper JUNOS 19.2 R1-S2

19.2

Juniper JUNOS 19.2 R1-S3

19.2

Juniper JUNOS 19.3

19.3

Juniper JUNOS 19.3 R1

19.3

Juniper JUNOS 19.3 R1-S1

19.3

Juniper JUNOS 19.3 R2

19.3

Juniper JUNOS 19.3 R2-S1

19.3

Juniper JUNOS 19.3 R2-S2

19.3

Juniper JUNOS 19.4 R1

19.4

Juniper JUNOS 19.4 R1-S1

19.4

Juniper JUNOS 20.1 R1

20.1

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