CVE-2021-32762 : Vulnerability Insights and Analysis

This article provides details on CVE-2021-32762, an integer overflow vulnerability affecting Redis versions. Learn about the impact, technical details, and mitigation strategies to address this security issue.

Understanding CVE-2021-32762

CVE-2021-32762 is an integer overflow vulnerability that can lead to a heap overflow in redis-cli and redis-sentinel on certain platforms.

What is CVE-2021-20657?

Redis, an open-source in-memory database, is susceptible to integer overflow when handling large multi-bulk network replies. This vulnerability arises from a flaw in the hiredis library, impacting systems with heap allocators lacking overflow checks.

The Impact of CVE-2021-32762

The vulnerability poses a high severity threat, with a CVSS base score of 7.5. It can be exploited remotely, leading to high impacts on confidentiality, integrity, and availability of affected systems.

Technical Details of CVE-2021-32762

CVE-2021-32762 is classified under two problem types: Integer Overflow or Wraparound (CWE-190) and Integer Overflow to Buffer Overflow (CWE-680).

Vulnerability Description

The vulnerability allows attackers to trigger a heap overflow by exploiting an integer overflow during the parsing of crafted network replies in redis-cli and redis-sentinel.

Affected Systems and Versions

Redis versions prior to 5.0.14, 6.0.16, and 6.2.6 are affected by this vulnerability, impacting systems with particular heap allocators.

Exploitation Mechanism

Malicious actors can exploit this vulnerability by sending specially crafted network replies to redis-cli and redis-sentinel, causing an integer overflow and subsequently a heap overflow.

Mitigation and Prevention

To address CVE-2021-32762, immediate actions and long-term security practices are necessary.

Immediate Steps to Take

Users are advised to update their Redis installations to version 5.0.14, 6.0.16, or 6.2.6 to mitigate the vulnerability. Additionally, monitoring network traffic for suspicious activity is recommended.

Long-Term Security Practices

Regularly applying software updates, conducting vulnerability assessments, and implementing secure coding practices can enhance the overall security posture of systems.

Patching and Updates

Stay informed about security advisories from Redis and related vendors to promptly apply patches and updates that address known vulnerabilities.