Critical Command Injection Vulnerability in Ubuntu Kylin Software Center
Severity: High (Score: 72.0)
Sources: launchpad.net, Linuxsecurity, Ubuntu
Published: · Updated:
Keywords: ubuntu, center, kylin, software, d-bus, input, usn-8424-1
Summary
A command injection vulnerability was identified in the Ubuntu Kylin Software Center's D-Bus method, allowing unprivileged local users to execute arbitrary commands with root privileges. The flaw arises from the use of `os.system()` with unsanitized user inputs, specifically the `src_path` and `app_fullname` parameters. An attacker could exploit this by crafting a malicious input, potentially modifying system files like `/etc/sudoers.d/`. The vulnerability is categorized as a local privilege escalation issue. An update has been released to implement cryptographic signature verification to mitigate the risk, but the underlying command injection issue remains unaddressed. Users are advised to update their systems to the latest package versions to apply the fix. The vulnerability affects all users of the Ubuntu Kylin Software Center who have access to the D-Bus service. Key Points: • A command injection vulnerability allows local users to gain root access via D-Bus. • Exploitation involves unsanitized inputs in the `copy_file_to_install` method. • An update adds signature verification but does not fully resolve the underlying issue.
Detailed Analysis
**Impact** Local unprivileged users on systems running Ubuntu Kylin Software Center are affected by this vulnerability, allowing them to escalate privileges to root. The issue impacts any deployment of Ubuntu Kylin where the vulnerable D-Bus service is enabled, potentially affecting users in sectors relying on this OS variant, primarily within China. The vulnerability enables unauthorized administrative access, risking system integrity and control but does not directly expose data theft or exfiltration. **Technical Details** The vulnerability arises from command injection via the `copy_file_to_install` D-Bus method, which uses `os.system()` with unsanitized user input (`src_path` and `app_fullname`). The D-Bus service runs as root with a permissive policy allowing any local user to invoke the method without authentication. Exploitation occurs at the local privilege escalation stage of the kill chain, leveraging crafted input to execute arbitrary commands as root. No CVE identifier or malware/tool names are provided. The fix introduces cryptographic signature verification (MD5 + AES) to validate requests, but the underlying injection vector remains. **Recommended Response** Apply the updated ubuntu-kylin-software-center package immediately to enforce signature verification on D-Bus calls. Verify that software installations continue to function and that exploit attempts fail due to signature validation. Monitor for unauthorized modifications to `/etc/sudoers.d/` and failed D-Bus calls indicating exploit attempts. Future updates should replace unsafe `os.system()` calls with safer APIs; until then, restrict local user access where possible.
Source articles (3)
- USN-8424-1: Ubuntu Kylin Software Center vulnerability — Ubuntu · 2026-06-11
Ubuntu Kylin Software Center could be made to run programs as an administrator if it received specially crafted input via its D-Bus service. It was discovered that Ubuntu Kylin Software Center incorre… - Ubuntu 26.04 Kylin Software Center Critical Privilege Escalation USN-8424 — Linuxsecurity · 2026-06-11
A security issue affects these releases of Ubuntu and its derivatives: - Ubuntu 26.04 LTS Summary: Ubuntu Kylin Software Center could be made to run programs as an administrator if it received special… - 2154543 — launchpad.net · 2026-06-11
* The `copy_file_ to_install` D-Bus method in ubuntu- kylin-software- center uses `os.system()` with unsanitized user input (`src_path` and `app_fullname` parameters), allowing command injection. Sinc…
Timeline
- 2026-06-11 — Vulnerability discovered in Ubuntu Kylin Software Center: A command injection flaw was found in the D-Bus service, enabling local privilege escalation for unprivileged users.
- 2026-06-11 — Security notice published by Ubuntu: Ubuntu issued USN-8424-1 detailing the vulnerability and recommending system updates for affected users.
- 2026-06-11 — Update released to mitigate vulnerability: An update was made available that adds cryptographic signature verification to the D-Bus method.
Related entities
- Command Injection (Attack Type)
- Privilege Escalation (Attack Type)
- Zero-day Exploit (Attack Type)
- CWE-269 - Improper Privilege Management (Cwe)
- CWE-78 - OS Command Injection (Cwe)
- T1059.004 - Unix Shell (Mitre Attack)
- T1068 - Exploitation for Privilege Escalation (Mitre Attack)
- Linux (Platform)
- Ubuntu Kylin (Platform)
- Kylin_ Softwarecenter_ Privesc. Py (Tool)