The vulnerability identified as CVE-2021-41495 is a Null Pointer Dereference vulnerability found in the numpy.sort function in NumPy version 1.19 and earlier. This flaw arises from a lack of return-value validation in the PyArray_DescrNew function. Attackers may exploit this vulnerability to conduct denial of service (DoS) attacks by repetitively creating sort arrays. It is important to note that while the validation is indeed missing, an error can only occur if the memory is exhausted, implying that an attacker needs to have some level of privilege to trigger such an event.
The CVSS score for this vulnerability is 5.3, categorizing it as medium severity. Given the nature of the vulnerability and its potential impact on system availability, organizations utilizing NumPy should take this issue seriously. The risk to organizations includes possible service disruptions if an attacker successfully manages to exhaust memory resources, thereby affecting application performance and availability.
As of now, there are no confirmed public exploits available, and the vulnerability has not been included in the Known Exploited Vulnerabilities (KEV) catalog. However, organizations should prioritize patching this vulnerability immediately to mitigate any potential risks.
Given the medium severity of this vulnerability, it is advisable for organizations to address it in their priority patch cycle. Regular monitoring and validation of patches will also be essential to ensure that systems remain secure against this and similar vulnerabilities.
Vulnerability Details
CVE-2021-41495 is classified as a Null Pointer Dereference vulnerability, specifically affecting the numpy.sort function in NumPy versions prior to 1.19. The missing return-value validation in the PyArray_DescrNew function is the root cause of the vulnerability, which can lead to denial of service. The CVSS base score is 5.3, reflecting medium severity, with the attack vector being network-based.
The CVSS vector string is CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H. The vulnerability is categorized under CWE-476, which indicates a null pointer dereference issue. Given the impact on availability, organizations using affected versions of NumPy must take immediate action.
Technical Analysis
The root cause of CVE-2021-41495 is the absence of proper validation in the PyArray_DescrNew function within NumPy. This flaw allows attackers to repeatedly create sort arrays, leading to potential memory exhaustion. The attack vector is classified as network-based, which means an attacker can exploit this vulnerability remotely. The complexity of the attack is high, requiring low privileges, and no user interaction is needed.
In terms of potential impact, the availability is significantly affected, with a high impact on the system's operational capacity. However, confidentiality and integrity impacts are rated as none. Organizations should be aware of the potential consequences of this vulnerability and take necessary measures to protect their systems.
Risk & Impact Analysis
The real-world risk associated with this vulnerability includes possible service disruptions and application downtime. Organizations leveraging NumPy in critical applications face a significant blast radius if this vulnerability is successfully exploited. Given its medium severity, organizations should assess the urgency based on their operational context.
Organizations should prioritize addressing this vulnerability in alignment with their patch management policies. The risk of exploitation, while currently low due to the absence of known exploits, could increase as threat actors continually seek out vulnerabilities in widely used libraries like NumPy.
Exploitation Status
Signal | Status |
|---|---|
Known Exploit | No |
Public PoC | No |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
The versions affected by this vulnerability include all versions of NumPy prior to 1.19. Organizations should ensure they are running the latest version to mitigate this risk.
Mitigation & Remediation
To mitigate the risks associated with CVE-2021-41495, organizations are advised to update to the latest version of NumPy. Regularly applying security patches and updates is crucial. In cases where immediate updating is not possible, consider implementing network controls and monitoring to detect any unusual behavior that may indicate attempts to exploit this vulnerability.
For comprehensive security assessments and to identify similar vulnerabilities, organizations should consider engaging in application security assessments that can help strengthen their defenses.
Detection Guidance
To detect potential exploitation of this vulnerability, organizations should monitor for log indicators that suggest abnormal memory usage patterns. Behavioral anomalies such as repeated failures in sorting operations may also signify attempts to exploit this vulnerability. Additionally, establishing network signatures that identify unusual traffic patterns can help in early detection.
AppSecure Threat Intelligence Insight
CVE-2021-41495 represents the ongoing challenges in maintaining software security, especially in widely used libraries like NumPy. As organizations increasingly rely on third-party libraries for critical functionality, the importance of robust security practices cannot be overstated. Security teams should conduct regular vulnerability assessments to identify and remediate issues proactively.
For structured guidance on vulnerability management, organizations can refer to the vulnerability management program design resources available.
Moreover, employing proactive security strategies such as penetration testing methodologies can help organizations better prepare for potential threats.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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