CVE-2020-27618 : Security Advisory and Response

CVE-2020-27618 is a vulnerability in the GNU C Library (glibc) that can lead to denial of service due to an infinite loop when processing certain invalid multi-byte input sequences.

Understanding CVE-2020-27618

This CVE affects glibc versions 2.32 and earlier, specifically when handling invalid multi-byte input sequences in various IBM encodings.

What is CVE-2020-27618?

The iconv function in glibc fails to advance the input state when processing specific multi-byte input sequences, potentially causing applications to enter an infinite loop, resulting in a denial of service.

The Impact of CVE-2020-27618

The vulnerability can be exploited to trigger a denial of service condition, affecting the availability of applications and systems relying on the affected glibc versions.

Technical Details of CVE-2020-27618

Vulnerability Description

Vulnerability in the iconv function of glibc 2.32 and earlier
Failure to advance input state when processing invalid multi-byte input sequences

Affected Systems and Versions

GNU C Library (glibc) versions 2.32 and earlier
Specifically impacted when handling invalid multi-byte input sequences in IBM1364, IBM1371, IBM1388, IBM1390, and IBM1399 encodings

Exploitation Mechanism

Exploiting the vulnerability can lead to an infinite loop in applications, causing a denial of service

Mitigation and Prevention

Immediate Steps to Take

Apply patches provided by the GNU C Library maintainers
Monitor vendor advisories for updates and apply security patches promptly

Long-Term Security Practices

Regularly update software and libraries to the latest versions
Implement input validation mechanisms to prevent malformed input

Patching and Updates

Update glibc to a patched version that addresses CVE-2020-27618