CVE-2021-38528 Vulnerability Analysis & Exploit Details

CVE-2021-38528
Vulnerability Scoring

9.6
/10
Critical Risk

As a catastrophic security flaw, CVE-2021-38528 has severe implications, demanding immediate intervention.

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: Changed
    Successful exploitation can impact components beyond the vulnerable component.
  • User Interaction: None
    No user interaction is necessary for exploitation.

CVE-2021-38528 Details

Status: Modified

Last updated: 🕕 21 Nov 2024, 06:17 UTC
Originally published on: 🕛 11 Aug 2021, 00:16 UTC

Time between publication and last update: 1198 days

CVSS Release: version 3

CVSS3 Source

cve@mitre.org

CVSS3 Type

Secondary

CVSS3 Vector

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

CVE-2021-38528 Vulnerability Summary

CVE-2021-38528: Certain NETGEAR devices are affected by command injection by an unauthenticated attacker. This affects D8500 before 1.0.3.58, R6900P before 1.3.2.132, R7000P before 1.3.2.132, R7100LG before 1.0.0.64, WNDR3400v3 before 1.0.1.38, and XR300 before 1.0.3.56.

Assessing the Risk of CVE-2021-38528

Access Complexity Graph

The exploitability of CVE-2021-38528 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-2021-38528

With low attack complexity and no required privileges, CVE-2021-38528 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-2021-38528, 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-2021-38528, 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-2021-38528 can result in unauthorized access to sensitive data, severely compromising data privacy.
  • Integrity: High
    CVE-2021-38528 could allow unauthorized modifications to data, potentially affecting system reliability and trust.
  • Availability: High
    CVE-2021-38528 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: 0.53% (probability of exploit)

EPSS Percentile: 77.34% (lower percentile = lower relative risk)
This vulnerability is less risky than approximately 22.659999999999997% of others.

CVE-2021-38528 References

External References

CWE Common Weakness Enumeration

CWE-77

CAPEC Common Attack Pattern Enumeration and Classification

  • LDAP Injection CAPEC-136 An attacker manipulates or crafts an LDAP query for the purpose of undermining the security of the target. Some applications use user input to create LDAP queries that are processed by an LDAP server. For example, a user might provide their username during authentication and the username might be inserted in an LDAP query during the authentication process. An attacker could use this input to inject additional commands into an LDAP query that could disclose sensitive information. For example, entering a * in the aforementioned query might return information about all users on the system. This attack is very similar to an SQL injection attack in that it manipulates a query to gather additional information or coerce a particular return value.
  • Command Delimiters CAPEC-15 An attack of this type exploits a programs' vulnerabilities that allows an attacker's commands to be concatenated onto a legitimate command with the intent of targeting other resources such as the file system or database. The system that uses a filter or denylist input validation, as opposed to allowlist validation is vulnerable to an attacker who predicts delimiters (or combinations of delimiters) not present in the filter or denylist. As with other injection attacks, the attacker uses the command delimiter payload as an entry point to tunnel through the application and activate additional attacks through SQL queries, shell commands, network scanning, and so on.
  • IMAP/SMTP Command Injection CAPEC-183 An adversary exploits weaknesses in input validation on web-mail servers to execute commands on the IMAP/SMTP server. Web-mail servers often sit between the Internet and the IMAP or SMTP mail server. User requests are received by the web-mail servers which then query the back-end mail server for the requested information and return this response to the user. In an IMAP/SMTP command injection attack, mail-server commands are embedded in parts of the request sent to the web-mail server. If the web-mail server fails to adequately sanitize these requests, these commands are then sent to the back-end mail server when it is queried by the web-mail server, where the commands are then executed. This attack can be especially dangerous since administrators may assume that the back-end server is protected against direct Internet access and therefore may not secure it adequately against the execution of malicious commands.
  • Command Injection CAPEC-248 An adversary looking to execute a command of their choosing, injects new items into an existing command thus modifying interpretation away from what was intended. Commands in this context are often standalone strings that are interpreted by a downstream component and cause specific responses. This type of attack is possible when untrusted values are used to build these command strings. Weaknesses in input validation or command construction can enable the attack and lead to successful exploitation.
  • Manipulating Writeable Terminal Devices CAPEC-40 This attack exploits terminal devices that allow themselves to be written to by other users. The attacker sends command strings to the target terminal device hoping that the target user will hit enter and thereby execute the malicious command with their privileges. The attacker can send the results (such as copying /etc/passwd) to a known directory and collect once the attack has succeeded.
  • Exploiting Multiple Input Interpretation Layers CAPEC-43 An attacker supplies the target software with input data that contains sequences of special characters designed to bypass input validation logic. This exploit relies on the target making multiples passes over the input data and processing a "layer" of special characters with each pass. In this manner, the attacker can disguise input that would otherwise be rejected as invalid by concealing it with layers of special/escape characters that are stripped off by subsequent processing steps. The goal is to first discover cases where the input validation layer executes before one or more parsing layers. That is, user input may go through the following logic in an application: <parser1> --> <input validator> --> <parser2>. In such cases, the attacker will need to provide input that will pass through the input validator, but after passing through parser2, will be converted into something that the input validator was supposed to stop.
  • Manipulating Writeable Configuration Files CAPEC-75 Generally these are manually edited files that are not in the preview of the system administrators, any ability on the attackers' behalf to modify these files, for example in a CVS repository, gives unauthorized access directly to the application, the same as authorized users.
  • Manipulating Web Input to File System Calls CAPEC-76 An attacker manipulates inputs to the target software which the target software passes to file system calls in the OS. The goal is to gain access to, and perhaps modify, areas of the file system that the target software did not intend to be accessible.

Vulnerable Configurations

  • cpe:2.3:o:netgear:d8500_firmware:-:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:d8500_firmware:-:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:d8500_firmware:1.0.3.27:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:d8500_firmware:1.0.3.27:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:d8500_firmware:1.0.3.28:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:d8500_firmware:1.0.3.28:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:d8500_firmware:1.0.3.29:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:d8500_firmware:1.0.3.29:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:d8500_firmware:1.0.3.35:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:d8500_firmware:1.0.3.35:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:d8500_firmware:1.0.3.36:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:d8500_firmware:1.0.3.36:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:d8500_firmware:1.0.3.39:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:d8500_firmware:1.0.3.39:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:d8500_firmware:1.0.3.42:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:d8500_firmware:1.0.3.42:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:d8500_firmware:1.0.3.43:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:d8500_firmware:1.0.3.43:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:d8500_firmware:1.0.3.44:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:d8500_firmware:1.0.3.44:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:d8500_firmware:1.0.3.50:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:d8500_firmware:1.0.3.50:*:*:*:*:*:*:*
  • cpe:2.3:h:netgear:d8500:-:*:*:*:*:*:*:*
    cpe:2.3:h:netgear:d8500:-:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:r6900p_firmware:-:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:r6900p_firmware:-:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:r6900p_firmware:1.0.0.56:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:r6900p_firmware:1.0.0.56:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:r6900p_firmware:1.0.0.58:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:r6900p_firmware:1.0.0.58:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:r6900p_firmware:1.0.0.62:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:r6900p_firmware:1.0.0.62:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:r6900p_firmware:1.0.1.16:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:r6900p_firmware:1.0.1.16:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:r6900p_firmware:1.2.0.22:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:r6900p_firmware:1.2.0.22:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:r6900p_firmware:1.3.0.8:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:r6900p_firmware:1.3.0.8:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:r6900p_firmware:1.3.0.18:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:r6900p_firmware:1.3.0.18:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:r6900p_firmware:1.3.0.20:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:r6900p_firmware:1.3.0.20:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:r6900p_firmware:1.3.1.26:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:r6900p_firmware:1.3.1.26:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:r6900p_firmware:1.3.1.44:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:r6900p_firmware:1.3.1.44:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:r6900p_firmware:1.3.1.64:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:r6900p_firmware:1.3.1.64:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:r6900p_firmware:1.3.2.34:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:r6900p_firmware:1.3.2.34:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:r6900p_firmware:1.3.2.124:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:r6900p_firmware:1.3.2.124:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:r6900p_firmware:1.3.2.126:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:r6900p_firmware:1.3.2.126:*:*:*:*:*:*:*
  • cpe:2.3:h:netgear:r6900p:-:*:*:*:*:*:*:*
    cpe:2.3:h:netgear:r6900p:-:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:r7000p_firmware:-:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:r7000p_firmware:-:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:r7000p_firmware:1.0.0.56:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:r7000p_firmware:1.0.0.56:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:r7000p_firmware:1.0.0.58:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:r7000p_firmware:1.0.0.58:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:r7000p_firmware:1.0.0.62:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:r7000p_firmware:1.0.0.62:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:r7000p_firmware:1.0.0.86:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:r7000p_firmware:1.0.0.86:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:r7000p_firmware:1.0.1.16:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:r7000p_firmware:1.0.1.16:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:r7000p_firmware:1.2.0.22:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:r7000p_firmware:1.2.0.22:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:r7000p_firmware:1.3.0.8:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:r7000p_firmware:1.3.0.8:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:r7000p_firmware:1.3.0.18:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:r7000p_firmware:1.3.0.18:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:r7000p_firmware:1.3.0.20:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:r7000p_firmware:1.3.0.20:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:r7000p_firmware:1.3.1.26:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:r7000p_firmware:1.3.1.26:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:r7000p_firmware:1.3.1.44:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:r7000p_firmware:1.3.1.44:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:r7000p_firmware:1.3.1.64:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:r7000p_firmware:1.3.1.64:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:r7000p_firmware:1.3.2.34:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:r7000p_firmware:1.3.2.34:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:r7000p_firmware:1.3.2.124:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:r7000p_firmware:1.3.2.124:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:r7000p_firmware:1.3.2.126:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:r7000p_firmware:1.3.2.126:*:*:*:*:*:*:*
  • cpe:2.3:h:netgear:r7000p:-:*:*:*:*:*:*:*
    cpe:2.3:h:netgear:r7000p:-:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:r7100lg_firmware:-:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:r7100lg_firmware:-:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:r7100lg_firmware:1.0.0.28:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:r7100lg_firmware:1.0.0.28:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:r7100lg_firmware:1.0.0.30:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:r7100lg_firmware:1.0.0.30:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:r7100lg_firmware:1.0.0.32:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:r7100lg_firmware:1.0.0.32:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:r7100lg_firmware:1.0.0.34:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:r7100lg_firmware:1.0.0.34:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:r7100lg_firmware:1.0.0.40:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:r7100lg_firmware:1.0.0.40:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:r7100lg_firmware:1.0.0.42:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:r7100lg_firmware:1.0.0.42:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:r7100lg_firmware:1.0.0.46:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:r7100lg_firmware:1.0.0.46:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:r7100lg_firmware:1.0.0.48:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:r7100lg_firmware:1.0.0.48:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:r7100lg_firmware:1.0.0.50:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:r7100lg_firmware:1.0.0.50:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:r7100lg_firmware:1.0.0.52:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:r7100lg_firmware:1.0.0.52:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:r7100lg_firmware:1.0.0.56:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:r7100lg_firmware:1.0.0.56:*:*:*:*:*:*:*
  • cpe:2.3:h:netgear:r7100lg:-:*:*:*:*:*:*:*
    cpe:2.3:h:netgear:r7100lg:-:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:wndr3400_firmware:-:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:wndr3400_firmware:-:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:wndr3400_firmware:1.0.1.8:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:wndr3400_firmware:1.0.1.8:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:wndr3400_firmware:1.0.1.12:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:wndr3400_firmware:1.0.1.12:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:wndr3400_firmware:1.0.1.14:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:wndr3400_firmware:1.0.1.14:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:wndr3400_firmware:1.0.1.16:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:wndr3400_firmware:1.0.1.16:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:wndr3400_firmware:1.0.1.18:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:wndr3400_firmware:1.0.1.18:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:wndr3400_firmware:1.0.1.22:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:wndr3400_firmware:1.0.1.22:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:wndr3400_firmware:1.0.1.24:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:wndr3400_firmware:1.0.1.24:*:*:*:*:*:*:*
  • cpe:2.3:h:netgear:wndr3400:v3:*:*:*:*:*:*:*
    cpe:2.3:h:netgear:wndr3400:v3:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:xr300_firmware:-:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:xr300_firmware:-:*:*:*:*:*:*:*
  • cpe:2.3:o:netgear:xr300_firmware:1.0.3.50:*:*:*:*:*:*:*
    cpe:2.3:o:netgear:xr300_firmware:1.0.3.50:*:*:*:*:*:*:*
  • cpe:2.3:h:netgear:xr300:-:*:*:*:*:*:*:*
    cpe:2.3:h:netgear:xr300:-:*:*:*:*:*:*:*

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