CVE-2018-0051 - Improper Input Validation

Severity

43%

Complexity

86%

Confidentiality

48%

A Denial of Service vulnerability in the SIP application layer gateway (ALG) component of Junos OS based platforms allows an attacker to crash MS-PIC, MS-MIC, MS-MPC, MS-DPC or SRX flow daemon (flowd) process. This issue affects Junos OS devices with NAT or stateful firewall configuration in combination with the SIP ALG enabled. SIP ALG is enabled by default on SRX Series devices except for SRX-HE devices. SRX-HE devices have SIP ALG disabled by default. The status of ALGs in SRX device can be obtained by executing the command: show security alg status Affected releases are Juniper Networks Junos OS: 12.1X46 versions prior to 12.1X46-D77; 12.3X48 versions prior to 12.3X48-D70; 15.1X49 versions prior to 15.1X49-D140; 15.1 versions prior to 15.1R4-S9, 15.1R7-S1; 15.1F6; 16.1 versions prior to 16.1R4-S9, 16.1R6-S1, 16.1R7; 16.2 versions prior to 16.2R2-S7, 16.2R3; 17.1 versions prior to 17.1R2-S7, 17.1R3; 17.2 versions prior to 17.2R1-S6, 17.2R2-S4, 17.2R3; 17.3 versions prior to 17.3R1-S5, 17.3R2-S2, 17.3R3; 17.4 versions prior to 17.4R2. No other Juniper Networks products or platforms are affected by this issue.

A Denial of Service vulnerability in the SIP application layer gateway (ALG) component of Junos OS based platforms allows an attacker to crash MS-PIC, MS-MIC, MS-MPC, MS-DPC or SRX flow daemon (flowd) process. This issue affects Junos OS devices with NAT or stateful firewall configuration in combination with the SIP ALG enabled. SIP ALG is enabled by default on SRX Series devices except for SRX-HE devices. SRX-HE devices have SIP ALG disabled by default. The status of ALGs in SRX device can be obtained by executing the command: show security alg status Affected releases are Juniper Networks Junos OS: 12.1X46 versions prior to 12.1X46-D77; 12.3X48 versions prior to 12.3X48-D70; 15.1X49 versions prior to 15.1X49-D140; 15.1 versions prior to 15.1R4-S9, 15.1R7-S1; 15.1F6; 16.1 versions prior to 16.1R4-S9, 16.1R6-S1, 16.1R7; 16.2 versions prior to 16.2R2-S7, 16.2R3; 17.1 versions prior to 17.1R2-S7, 17.1R3; 17.2 versions prior to 17.2R1-S6, 17.2R2-S4, 17.2R3; 17.3 versions prior to 17.3R1-S5, 17.3R2-S2, 17.3R3; 17.4 versions prior to 17.4R2. No other Juniper Networks products or platforms are affected by this issue.

CVSS 3.0 Base Score 5.9. CVSS Attack Vector: network. CVSS Attack Complexity: high. CVSS Vector: (CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H).

CVSS 2.0 Base Score 4.3. CVSS Attack Vector: network. CVSS Attack Complexity: medium. CVSS Vector: (AV:N/AC:M/Au:N/C:N/I:N/A:P).

Demo Examples

Improper Input Validation

CWE-20

This example demonstrates a shopping interaction in which the user is free to specify the quantity of items to be purchased and a total is calculated.


               
...

The user has no control over the price variable, however the code does not prevent a negative value from being specified for quantity. If an attacker were to provide a negative value, then the user would have their account credited instead of debited.

Improper Input Validation

CWE-20

This example asks the user for a height and width of an m X n game board with a maximum dimension of 100 squares.


               
.../* board dimensions */
die("No integer passed: Die evil hacker!\n");
die("No integer passed: Die evil hacker!\n");
die("Value too large: Die evil hacker!\n");

While this code checks to make sure the user cannot specify large, positive integers and consume too much memory, it does not check for negative values supplied by the user. As a result, an attacker can perform a resource consumption (CWE-400) attack against this program by specifying two, large negative values that will not overflow, resulting in a very large memory allocation (CWE-789) and possibly a system crash. Alternatively, an attacker can provide very large negative values which will cause an integer overflow (CWE-190) and unexpected behavior will follow depending on how the values are treated in the remainder of the program.

Improper Input Validation

CWE-20

The following example shows a PHP application in which the programmer attempts to display a user's birthday and homepage.


               
echo "Birthday: $birthday<br>Homepage: <a href=$homepage>click here</a>"

The programmer intended for $birthday to be in a date format and $homepage to be a valid URL. However, since the values are derived from an HTTP request, if an attacker can trick a victim into clicking a crafted URL with <script> tags providing the values for birthday and / or homepage, then the script will run on the client's browser when the web server echoes the content. Notice that even if the programmer were to defend the $birthday variable by restricting input to integers and dashes, it would still be possible for an attacker to provide a string of the form:


               
2009-01-09--

If this data were used in a SQL statement, it would treat the remainder of the statement as a comment. The comment could disable other security-related logic in the statement. In this case, encoding combined with input validation would be a more useful protection mechanism.

Furthermore, an XSS (CWE-79) attack or SQL injection (CWE-89) are just a few of the potential consequences when input validation is not used. Depending on the context of the code, CRLF Injection (CWE-93), Argument Injection (CWE-88), or Command Injection (CWE-77) may also be possible.

Improper Input Validation

CWE-20

This function attempts to extract a pair of numbers from a user-supplied string.


               
}
die("Did not specify integer value. Die evil hacker!\n");
/* proceed assuming n and m are initialized correctly */

This code attempts to extract two integer values out of a formatted, user-supplied input. However, if an attacker were to provide an input of the form:


               
123:

then only the m variable will be initialized. Subsequent use of n may result in the use of an uninitialized variable (CWE-457).

Improper Input Validation

CWE-20

The following example takes a user-supplied value to allocate an array of objects and then operates on the array.


               
}
list[0] = new Widget();
die("Negative value supplied for list size, die evil hacker!");

This example attempts to build a list from a user-specified value, and even checks to ensure a non-negative value is supplied. If, however, a 0 value is provided, the code will build an array of size 0 and then try to store a new Widget in the first location, causing an exception to be thrown.

Improper Input Validation

CWE-20

This application has registered to handle a URL when sent an intent:


               
}......
}
}
int length = URL.length();
...

The application assumes the URL will always be included in the intent. When the URL is not present, the call to getStringExtra() will return null, thus causing a null pointer exception when length() is called.

Overview

Type

Juniper

First reported 6 years ago

2018-10-10 18:29:00

Last updated 5 years ago

2019-10-09 23:31:00

Affected Software

Juniper JUNOS 12.1X46

12.1x46

Juniper Junos 12.1x46 D10

12.1x46

Juniper Junos 12.1x46 D15

12.1x46

Juniper JUNOS 12.1X46-D20

12.1x46

Juniper Junos 12.1x46 D25

12.1x46

Juniper JunOS 12.1x46 D30

12.1x46

Juniper JunOS 12.1x46 D35

12.1x46

Juniper JunOS 12.1x46 D40

12.1x46

Juniper Junos 12.1X46 D45

12.1x46

Juniper Junos 12.1X46 D50

12.1x46

Juniper JunOS 12.1X46 D55

12.1x46

Juniper JunOS 12.1X46 D60

12.1x46

Juniper Junos 12.1X46 D65

12.1x46

Juniper JunOS 12.3x48 D10

12.3x48

Juniper JunOS 12.3x48 D15

12.3x48

Juniper Junos OS 12.3X48 D20

12.3x48

Juniper Junos 12.3X48 D25

12.3x48

Juniper Junos OS 12.3X48 D30

12.3x48

Juniper Junos OS 12.3X48 D35

12.3x48

Juniper Junos OS 12.3X48 D40

12.3x48

Juniper Junos OS 12.3X48 D45

12.3x48

Juniper Junos OS 12.3X48 D50

12.3x48

Juniper Junos OS 12.3X48 D55

12.3x48

Juniper Junos OS 12.3X48 D60

12.3x48

Juniper Junos OS 12.3X48 D65

12.3x48

Juniper JunOS 15.1x49 D10

15.1x49

Juniper Junos OS 15.1X49 D100

15.1x49

Juniper Junos OS 15.1X49 D110

15.1x49

Juniper Junos OS 15.1X49 D120

15.1x49

Juniper Junos OS 15.1X49 D130

15.1x49

Juniper JunOS 15.1x49 D20

15.1x49

Juniper JunOS 15.1X49 D30

15.1x49

Juniper Junos 15.1X49 D35

15.1x49

Juniper JunOS 15.1X49 D40

15.1x49

Juniper JunOS 15.1X49 D45

15.1x49

Juniper JunOS 15.1X49 D50

15.1x49

Juniper JunOS 15.1X49 D55

15.1x49

Juniper JunOS 15.1X49 D60

15.1x49

Juniper JunOS 15.1X49 D65

15.1x49

Juniper JunOS 15.1X49 D75

15.1x49

Juniper JunOS 15.1X49 D80

15.1x49

Juniper Junos OS 15.1X49 D90

15.1x49

Juniper JUNOS 15.1 F6

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 R7-S1

15.1

Juniper JUNOS 16.1

16.1

Juniper JunOS 16.1 R1

16.1

Juniper JunOS 16.1 R2

16.1

Juniper JunOS 16.1 R3

16.1

Juniper Junos 16.1 R5

16.1

Juniper Junos 16.1 R6-S1

16.1

Juniper Junos 16.1 R7

16.1

Juniper JUNOS 16.2

16.2

Juniper JunOS 16.2 R1

16.2

Juniper JUNOS 16.2R3

16.2

Juniper JUNOS 17.1

17.1

Juniper JunOS 17.1 R1

17.1

Juniper Junos 17.1 R2

17.1

Juniper JUNOS 17.2

17.2

Juniper Junos 17.2 R1

17.2

Juniper JUNOS 17.3

17.3

Juniper JUNOS 17.3R2-S2

17.3

Juniper Junos 17.4

17.4

Juniper Junos 17.4 R1

17.4

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