CVE-2018-21205 Vulnerability Analysis & Exploit Details

CVE-2018-21205
Vulnerability Scoring

8.8
/10
Severe Risk

Cybersecurity professionals consider CVE-2018-21205 an immediate threat requiring urgent mitigation.

Attack Complexity Details

  • Attack Complexity: Low
    Exploits can be performed without significant complexity or special conditions.
  • Attack Vector: Adjacent_network
    Attack Vector Under Analysis
  • Privileges Required: None
    No privileges are required for exploitation.
  • Scope: Unchanged
    Exploit remains within the originally vulnerable component.
  • User Interaction: None
    No user interaction is necessary for exploitation.

CVE-2018-21205 Details

Status: Analyzed

Last updated: 🕘 05 May 2020, 21:08 UTC
Originally published on: 🕓 28 Apr 2020, 16:15 UTC

Time between publication and last update: 7 days

CVSS Release: version 3

CVSS3 Source

nvd@nist.gov

CVSS3 Type

Primary

CVSS3 Vector

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

CVE-2018-21205 Vulnerability Summary

CVE-2018-21205: Certain NETGEAR devices are affected by a stack-based buffer overflow by an unauthenticated attacker. This affects D7800 before 1.0.1.30, EX2700 before 1.0.1.28, R6100 before 1.0.1.20, R7500 before 1.0.0.118, R7500v2 before 1.0.3.24, R7800 before 1.0.2.40, R9000 before 1.0.2.52, WN2000RPTv3 before 1.0.1.20, WN3000RPv3 before 1.0.2.50, WN3100RPv2 before 1.0.0.56, WNDR3700v4 before 1.0.2.96, WNDR4300 before 1.0.2.98, WNDR4300v2 before 1.0.0.50, and WNDR4500v3 before 1.0.0.50.

Assessing the Risk of CVE-2018-21205

Access Complexity Graph

The exploitability of CVE-2018-21205 depends on two key factors: attack complexity (the level of effort required to execute an exploit) and privileges required (the access level an attacker needs).

Exploitability Analysis for CVE-2018-21205

With low attack complexity and no required privileges, CVE-2018-21205 is an easy target for cybercriminals. Organizations should prioritize immediate mitigation measures to prevent unauthorized access and data breaches.

Understanding AC and PR

A lower complexity and fewer privilege requirements make exploitation easier. Security teams should evaluate these aspects to determine the urgency of mitigation strategies, such as patch management and access control policies.

Attack Complexity (AC) measures the difficulty in executing an exploit. A high AC means that specific conditions must be met, making an attack more challenging, while a low AC means the vulnerability can be exploited with minimal effort.

Privileges Required (PR) determine the level of system access necessary for an attack. Vulnerabilities requiring no privileges are more accessible to attackers, whereas high privilege requirements limit exploitation to authorized users with elevated access.

CVSS Score Breakdown Chart

Above is the CVSS Sub-score Breakdown for CVE-2018-21205, illustrating how Base, Impact, and Exploitability factors combine to form the overall severity rating. A higher sub-score typically indicates a more severe or easier-to-exploit vulnerability.

CIA Impact Analysis

Below is the Impact Analysis for CVE-2018-21205, showing how Confidentiality, Integrity, and Availability might be affected if the vulnerability is exploited. Higher values usually signal greater potential damage.

  • Confidentiality: High
    Exploiting CVE-2018-21205 can result in unauthorized access to sensitive data, severely compromising data privacy.
  • Integrity: High
    CVE-2018-21205 could allow unauthorized modifications to data, potentially affecting system reliability and trust.
  • Availability: High
    CVE-2018-21205 can disrupt system operations, potentially causing complete denial of service (DoS).

Exploit Prediction Scoring System (EPSS)

The EPSS score estimates the probability that this vulnerability will be exploited in the near future.

EPSS Score: 0.079% (probability of exploit)

EPSS Percentile: 37.09% (lower percentile = lower relative risk)
This vulnerability is less risky than approximately 62.91% of others.

CVE-2018-21205 References

External References

CWE Common Weakness Enumeration

CWE-120

CAPEC Common Attack Pattern Enumeration and Classification

  • Buffer Overflow via Environment Variables CAPEC-10 This attack pattern involves causing a buffer overflow through manipulation of environment variables. Once the adversary finds that they can modify an environment variable, they may try to overflow associated buffers. This attack leverages implicit trust often placed in environment variables.
  • Overflow Buffers CAPEC-100 Buffer Overflow attacks target improper or missing bounds checking on buffer operations, typically triggered by input injected by an adversary. As a consequence, an adversary is able to write past the boundaries of allocated buffer regions in memory, causing a program crash or potentially redirection of execution as per the adversaries' choice.
  • Client-side Injection-induced Buffer Overflow CAPEC-14 This type of attack exploits a buffer overflow vulnerability in targeted client software through injection of malicious content from a custom-built hostile service. This hostile service is created to deliver the correct content to the client software. For example, if the client-side application is a browser, the service will host a webpage that the browser loads.
  • Filter Failure through Buffer Overflow CAPEC-24 In this attack, the idea is to cause an active filter to fail by causing an oversized transaction. An attacker may try to feed overly long input strings to the program in an attempt to overwhelm the filter (by causing a buffer overflow) and hoping that the filter does not fail securely (i.e. the user input is let into the system unfiltered).
  • MIME Conversion CAPEC-42 An attacker exploits a weakness in the MIME conversion routine to cause a buffer overflow and gain control over the mail server machine. The MIME system is designed to allow various different information formats to be interpreted and sent via e-mail. Attack points exist when data are converted to MIME compatible format and back.
  • Overflow Binary Resource File CAPEC-44 An attack of this type exploits a buffer overflow vulnerability in the handling of binary resources. Binary resources may include music files like MP3, image files like JPEG files, and any other binary file. These attacks may pass unnoticed to the client machine through normal usage of files, such as a browser loading a seemingly innocent JPEG file. This can allow the adversary access to the execution stack and execute arbitrary code in the target process.
  • Buffer Overflow via Symbolic Links CAPEC-45 This type of attack leverages the use of symbolic links to cause buffer overflows. An adversary can try to create or manipulate a symbolic link file such that its contents result in out of bounds data. When the target software processes the symbolic link file, it could potentially overflow internal buffers with insufficient bounds checking.
  • Overflow Variables and Tags CAPEC-46 This type of attack leverages the use of tags or variables from a formatted configuration data to cause buffer overflow. The adversary crafts a malicious HTML page or configuration file that includes oversized strings, thus causing an overflow.
  • Buffer Overflow via Parameter Expansion CAPEC-47 In this attack, the target software is given input that the adversary knows will be modified and expanded in size during processing. This attack relies on the target software failing to anticipate that the expanded data may exceed some internal limit, thereby creating a buffer overflow.
  • String Format Overflow in syslog() CAPEC-67 This attack targets applications and software that uses the syslog() function insecurely. If an application does not explicitely use a format string parameter in a call to syslog(), user input can be placed in the format string parameter leading to a format string injection attack. Adversaries can then inject malicious format string commands into the function call leading to a buffer overflow. There are many reported software vulnerabilities with the root cause being a misuse of the syslog() function.
  • Buffer Overflow in an API Call CAPEC-8 This attack targets libraries or shared code modules which are vulnerable to buffer overflow attacks. An adversary who has knowledge of known vulnerable libraries or shared code can easily target software that makes use of these libraries. All clients that make use of the code library thus become vulnerable by association. This has a very broad effect on security across a system, usually affecting more than one software process.
  • Buffer Overflow in Local Command-Line Utilities CAPEC-9 This attack targets command-line utilities available in a number of shells. An adversary can leverage a vulnerability found in a command-line utility to escalate privilege to root.
  • Forced Integer Overflow CAPEC-92 This attack forces an integer variable to go out of range. The integer variable is often used as an offset such as size of memory allocation or similarly. The attacker would typically control the value of such variable and try to get it out of range. For instance the integer in question is incremented past the maximum possible value, it may wrap to become a very small, or negative number, therefore providing a very incorrect value which can lead to unexpected behavior. At worst the attacker can execute arbitrary code.

Vulnerable Configurations

  • cpe:2.3:h:netgear:d7800:-:*:*:*:*:*:*:*
    cpe:2.3:h:netgear:d7800:-:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:d7800_firmware:1.0.1.22:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:d7800_firmware:1.0.1.22:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:d7800_firmware:1.0.1.24:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:d7800_firmware:1.0.1.24:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:d7800_firmware:1.0.1.28:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:d7800_firmware:1.0.1.28:*:*:*:*:*:*:*
  • cpe:2.3:h:netgear:ex2700:-:*:*:*:*:*:*:*
    cpe:2.3:h:netgear:ex2700:-:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:ex2700_firmware:-:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:ex2700_firmware:-:*:*:*:*:*:*:*
  • cpe:2.3:h:netgear:r6100:-:*:*:*:*:*:*:*
    cpe:2.3:h:netgear:r6100:-:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:r6100_firmware:1.0.1.1:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:r6100_firmware:1.0.1.1:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:r6100_firmware:1.0.1.12:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:r6100_firmware:1.0.1.12:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:r6100_firmware:1.0.1.14:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:r6100_firmware:1.0.1.14:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:r6100_firmware:1.0.1.16:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:r6100_firmware:1.0.1.16:*:*:*:*:*:*:*
  • cpe:2.3:h:netgear:r7500:-:*:*:*:*:*:*:*
    cpe:2.3:h:netgear:r7500:-:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:r7500_firmware:1.0.0.108:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:r7500_firmware:1.0.0.108:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:r7500_firmware:1.0.0.110:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:r7500_firmware:1.0.0.110:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:r7500_firmware:1.0.0.112:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:r7500_firmware:1.0.0.112:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:r7500_firmware:1.0.0.116:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:r7500_firmware:1.0.0.116:*:*:*:*:*:*:*
  • cpe:2.3:h:netgear:r7500:v2:*:*:*:*:*:*:*
    cpe:2.3:h:netgear:r7500:v2:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:r7500_firmware:1.0.0.118:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:r7500_firmware:1.0.0.118:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:r7500_firmware:1.0.0.122:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:r7500_firmware:1.0.0.122:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:r7500_firmware:1.0.0.124:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:r7500_firmware:1.0.0.124:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:r7500_firmware:1.0.0.130:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:r7500_firmware:1.0.0.130:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:r7500_firmware:1.0.3.10:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:r7500_firmware:1.0.3.10:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:r7500_firmware:1.0.3.16:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:r7500_firmware:1.0.3.16:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:r7500_firmware:1.0.3.20:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:r7500_firmware:1.0.3.20:*:*:*:*:*:*:*
  • cpe:2.3:h:netgear:r7800:-:*:*:*:*:*:*:*
    cpe:2.3:h:netgear:r7800:-:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:r7800_firmware:-:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:r7800_firmware:-:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:r7800_firmware:1.0.1.30:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:r7800_firmware:1.0.1.30:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:r7800_firmware:1.0.2.16:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:r7800_firmware:1.0.2.16:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:r7800_firmware:1.0.2.28:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:r7800_firmware:1.0.2.28:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:r7800_firmware:1.0.2.30:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:r7800_firmware:1.0.2.30:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:r7800_firmware:1.0.2.32:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:r7800_firmware:1.0.2.32:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:r7800_firmware:1.0.2.36:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:r7800_firmware:1.0.2.36:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:r7800_firmware:1.0.2.38:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:r7800_firmware:1.0.2.38:*:*:*:*:*:*:*
  • cpe:2.3:h:netgear:r900:-:*:*:*:*:*:*:*
    cpe:2.3:h:netgear:r900:-:*:*:*:*:*:*:*
  • cpe:2.3:h:netgear:wn2000rpt:v3:*:*:*:*:*:*:*
    cpe:2.3:h:netgear:wn2000rpt:v3:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:wn2000rpt_firmware:1.0.1.8:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:wn2000rpt_firmware:1.0.1.8:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:wn2000rpt_firmware:1.0.1.14:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:wn2000rpt_firmware:1.0.1.14:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:wn3000rp_firmware:1.0.0.52:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:wn3000rp_firmware:1.0.0.52:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:wn3000rp_firmware:1.0.0.56:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:wn3000rp_firmware:1.0.0.56:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:wn3000rp_firmware:1.0.0.68:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:wn3000rp_firmware:1.0.0.68:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:wn3000rp_firmware:1.0.2.44:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:wn3000rp_firmware:1.0.2.44:*:*:*:*:*:*:*
  • cpe:2.3:h:netgear:wn3000rp:v3:*:*:*:*:*:*:*
    cpe:2.3:h:netgear:wn3000rp:v3:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:wn3100rp_firmware:1.0.0.20:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:wn3100rp_firmware:1.0.0.20:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:wn3100rp_firmware:1.0.0.40:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:wn3100rp_firmware:1.0.0.40:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:wn3100rp_firmware:1.0.0.42:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:wn3100rp_firmware:1.0.0.42:*:*:*:*:*:*:*
  • cpe:2.3:h:netgear:wn3100rp:v2:*:*:*:*:*:*:*
    cpe:2.3:h:netgear:wn3100rp:v2:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:wndr3700_firmware:-:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:wndr3700_firmware:-:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:wndr3700_firmware:1.0.1.14:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:wndr3700_firmware:1.0.1.14:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:wndr3700_firmware:1.0.2.86:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:wndr3700_firmware:1.0.2.86:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:wndr3700_firmware:1.0.2.88:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:wndr3700_firmware:1.0.2.88:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:wndr3700_firmware:1.0.2.92:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:wndr3700_firmware:1.0.2.92:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:wndr3700_firmware:1.0.2.94:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:wndr3700_firmware:1.0.2.94:*:*:*:*:*:*:*
  • cpe:2.3:h:netgear:wndr3700:v4:*:*:*:*:*:*:*
    cpe:2.3:h:netgear:wndr3700:v4:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:wndr4300_firmware:1.0.0.48:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:wndr4300_firmware:1.0.0.48:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:wndr4300_firmware:1.0.0.50:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:wndr4300_firmware:1.0.0.50:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:wndr4300_firmware:1.0.0.52:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:wndr4300_firmware:1.0.0.52:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:wndr4300_firmware:1.0.0.54:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:wndr4300_firmware:1.0.0.54:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:wndr4300_firmware:1.0.0.56:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:wndr4300_firmware:1.0.0.56:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:wndr4300_firmware:1.0.0.58:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:wndr4300_firmware:1.0.0.58:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:wndr4300_firmware:1.0.2.88:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:wndr4300_firmware:1.0.2.88:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:wndr4300_firmware:1.0.2.90:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:wndr4300_firmware:1.0.2.90:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:wndr4300_firmware:1.0.2.92:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:wndr4300_firmware:1.0.2.92:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:wndr4300_firmware:1.0.2.94:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:wndr4300_firmware:1.0.2.94:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:wndr4300_firmware:1.0.2.96:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:wndr4300_firmware:1.0.2.96:*:*:*:*:*:*:*
  • cpe:2.3:h:netgear:wndr4300:-:*:*:*:*:*:*:*
    cpe:2.3:h:netgear:wndr4300:-:*:*:*:*:*:*:*
  • cpe:2.3:h:netgear:wndr4300:v2:*:*:*:*:*:*:*
    cpe:2.3:h:netgear:wndr4300:v2:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:wndr4500_firmware:-:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:wndr4500_firmware:-:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:wndr4500_firmware:1.0.0.48:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:wndr4500_firmware:1.0.0.48:*:*:*:*:*:*:*
  • cpe:2.3:h:netgear:wndr4500:v3:*:*:*:*:*:*:*
    cpe:2.3:h:netgear:wndr4500:v3:*:*:*:*:*:*:*

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