CVE-2018-20164 Vulnerability Analysis & Exploit Details

CVE-2018-20164
Vulnerability Scoring

5.3
/10
Significant Risk

Security assessments indicate that CVE-2018-20164 presents a notable risk, potentially requiring prompt mitigation.

Attack Complexity Details

  • Attack Complexity: Low
    Exploits can be performed without significant complexity or special conditions.
  • Attack Vector: Network
    Vulnerability is exploitable over a network without physical access.
  • 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-2018-20164 Details

Status: Modified

Last updated: 🕓 21 Nov 2024, 04:00 UTC
Originally published on: 🕑 13 Feb 2019, 14:29 UTC

Time between publication and last update: 2107 days

CVSS Release: version 3

CVSS3 Source

nvd@nist.gov

CVSS3 Type

Primary

CVSS3 Vector

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

CVE-2018-20164 Vulnerability Summary

CVE-2018-20164: An issue was discovered in regex.yaml (aka regexes.yaml) in UA-Parser UAP-Core before 0.6.0. A Regular Expression Denial of Service (ReDoS) issue allows remote attackers to overload a server by setting the User-Agent header in an HTTP(S) request to a value containing a long digit string. (The UAP-Core project contains the vulnerability, propagating to all implementations.)

Assessing the Risk of CVE-2018-20164

Access Complexity Graph

The exploitability of CVE-2018-20164 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-2018-20164

With low attack complexity and no required privileges, CVE-2018-20164 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-2018-20164, 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-2018-20164, showing how Confidentiality, Integrity, and Availability might be affected if the vulnerability is exploited. Higher values usually signal greater potential damage.

  • Confidentiality: None
    CVE-2018-20164 has no significant impact on data confidentiality.
  • Integrity: None
    CVE-2018-20164 poses no threat to data integrity.
  • Availability: Low
    CVE-2018-20164 may slightly degrade system performance without fully affecting service availability.

Exploit Prediction Scoring System (EPSS)

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

EPSS Score: 0.652% (probability of exploit)

EPSS Percentile: 79.77% (lower percentile = lower relative risk)
This vulnerability is less risky than approximately 20.230000000000004% of others.

CVE-2018-20164 References

External References

CWE Common Weakness Enumeration

CWE-185

CAPEC Common Attack Pattern Enumeration and Classification

  • 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.
  • Argument Injection CAPEC-6 An attacker changes the behavior or state of a targeted application through injecting data or command syntax through the targets use of non-validated and non-filtered arguments of exposed services or methods.
  • Using Slashes in Alternate Encoding CAPEC-79 This attack targets the encoding of the Slash characters. An adversary would try to exploit common filtering problems related to the use of the slashes characters to gain access to resources on the target host. Directory-driven systems, such as file systems and databases, typically use the slash character to indicate traversal between directories or other container components. For murky historical reasons, PCs (and, as a result, Microsoft OSs) choose to use a backslash, whereas the UNIX world typically makes use of the forward slash. The schizophrenic result is that many MS-based systems are required to understand both forms of the slash. This gives the adversary many opportunities to discover and abuse a number of common filtering problems. The goal of this pattern is to discover server software that only applies filters to one version, but not the other.

Vulnerable Configurations

  • cpe:2.3:a:uaparser:user_agent_parser-core:0.1.0:*:*:*:*:*:*:*
    cpe:2.3:a:uaparser:user_agent_parser-core:0.1.0:*:*:*:*:*:*:*
  • cpe:2.3:a:uaparser:user_agent_parser-core:0.1.1:*:*:*:*:*:*:*
    cpe:2.3:a:uaparser:user_agent_parser-core:0.1.1:*:*:*:*:*:*:*
  • cpe:2.3:a:uaparser:user_agent_parser-core:0.1.2:*:*:*:*:*:*:*
    cpe:2.3:a:uaparser:user_agent_parser-core:0.1.2:*:*:*:*:*:*:*
  • cpe:2.3:a:uaparser:user_agent_parser-core:0.2.0:*:*:*:*:*:*:*
    cpe:2.3:a:uaparser:user_agent_parser-core:0.2.0:*:*:*:*:*:*:*
  • cpe:2.3:a:uaparser:user_agent_parser-core:0.2.1:*:*:*:*:*:*:*
    cpe:2.3:a:uaparser:user_agent_parser-core:0.2.1:*:*:*:*:*:*:*
  • cpe:2.3:a:uaparser:user_agent_parser-core:0.2.2:*:*:*:*:*:*:*
    cpe:2.3:a:uaparser:user_agent_parser-core:0.2.2:*:*:*:*:*:*:*
  • cpe:2.3:a:uaparser:user_agent_parser-core:0.2.3:*:*:*:*:*:*:*
    cpe:2.3:a:uaparser:user_agent_parser-core:0.2.3:*:*:*:*:*:*:*
  • cpe:2.3:a:uaparser:user_agent_parser-core:0.2.4:*:*:*:*:*:*:*
    cpe:2.3:a:uaparser:user_agent_parser-core:0.2.4:*:*:*:*:*:*:*
  • cpe:2.3:a:uaparser:user_agent_parser-core:0.3.0:*:*:*:*:*:*:*
    cpe:2.3:a:uaparser:user_agent_parser-core:0.3.0:*:*:*:*:*:*:*
  • cpe:2.3:a:uaparser:user_agent_parser-core:0.3.1:*:*:*:*:*:*:*
    cpe:2.3:a:uaparser:user_agent_parser-core:0.3.1:*:*:*:*:*:*:*
  • cpe:2.3:a:uaparser:user_agent_parser-core:0.3.2:*:*:*:*:*:*:*
    cpe:2.3:a:uaparser:user_agent_parser-core:0.3.2:*:*:*:*:*:*:*
  • cpe:2.3:a:uaparser:user_agent_parser-core:0.3.4:*:*:*:*:*:*:*
    cpe:2.3:a:uaparser:user_agent_parser-core:0.3.4:*:*:*:*:*:*:*
  • cpe:2.3:a:uaparser:user_agent_parser-core:0.4.0:*:*:*:*:*:*:*
    cpe:2.3:a:uaparser:user_agent_parser-core:0.4.0:*:*:*:*:*:*:*
  • cpe:2.3:a:uaparser:user_agent_parser-core:0.5.0:*:*:*:*:*:*:*
    cpe:2.3:a:uaparser:user_agent_parser-core:0.5.0:*:*:*:*:*:*:*

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