CVE-2020-15229 : Exploit Details and Defense Strategies

Singularity, an open-source container platform, versions 3.1.1 through 3.6.3, is vulnerable to path traversal and file overwrite due to insecure handling of

unsquashfs

.

Understanding CVE-2020-15229

Singularity versions 3.1.1 through 3.6.3 are susceptible to a critical vulnerability that allows attackers to overwrite or create files on the host filesystem during the extraction process.

What is CVE-2020-15229?

The vulnerability arises from the insecure handling of path traversal and the lack of path sanitization within

unsquashfs

, enabling malicious actors to manipulate files during extraction, potentially leading to system compromise.

The Impact of CVE-2020-15229

CVSS Base Score: 8.2 (High Severity)
Attack Vector: Network
Integrity Impact: High
Confidentiality Impact: Low
Privileges Required: None
Scope: Changed
User Interaction: Required
The vulnerability poses a significant risk to system integrity, allowing unauthorized file manipulation and potential system compromise.

Technical Details of CVE-2020-15229

Singularity's vulnerability to path traversal and file overwrite with

unsquashfs

has the following technical implications:

Vulnerability Description

The flaw allows attackers to overwrite or create files on the host filesystem during the extraction process.

Affected Systems and Versions

Product: Singularity
Vendor: HPCng
Versions Affected: < 3.6.4

Exploitation Mechanism

Attack Complexity: Low
Attack Vector: Network
Privileges Required: None
User Interaction: Required
The vulnerability can be exploited remotely without the need for user privileges, making it a high-risk threat.

Mitigation and Prevention

To address CVE-2020-15229, users and administrators should take the following steps:

Immediate Steps to Take

Upgrade Singularity to version 3.6.4 to mitigate the vulnerability.
Avoid using unprivileged mode with single file images; opt for sandbox images instead.

Long-Term Security Practices

Use

--fakeroot

or a virtual machine (VM) when building images from

library

and

shub

sources.

Patching and Updates

Regularly update Singularity to the latest version to ensure protection against known vulnerabilities.