1 Vulnerability Overview
Recently, a security researcher discovered a critical vulnerability in the Advanced Packaging Tool (APT) of Linux. This vulnerability stems from the APT’s failure to properly handle redirects, which can be triggered via a man-in-the-middle attack or a malicious package mirror, resulting in remote code execution.
By changing the flag bit of the response, an attacker can redirect the download link of an installation package to a malicious server. In this case, if the attacker also changes the hash in communication data to that of the malicious package, he or she can get by the local authentication of the APT. The attacker can then trigger the vulnerability via a man-in-the-middle attack in the network environment or the mirror download server controlled by him or her, so as to execute malicious code with root privileges.
2 Scope of Impact
- Ubuntu 18.10 apt < 1.7.0ubuntu0.1
- Ubuntu 18.04 LTS apt < 1.6.6ubuntu0.1
- Ubuntu 16.04 LTS apt < 1.2.29ubuntu0.1
- Ubuntu 14.04 LTS apt < 1.0.1ubuntu2.19
- Debian apt 1.8.0- alpha3
- Debian apt 1.4.8
- Debian apt 126.96.36.199
- Ubuntu 18.10 apt – 1.7.0ubuntu0.1
- Ubuntu 18.04 LTS apt – 1.6.6ubuntu0.1
- Ubuntu 16.04 LTS apt – 1.2.29ubuntu0.1
- Ubuntu 14.04 LTS apt – 1.0.1ubuntu2.19
- Debian apt 1.8.0- alpha3.1
- Debian apt 188.8.131.52.5
- Debian apt 1.4.9
3 Vulnerability Check
3.1 Version Check
Users can run the following command to query the APT version of the current system. If the version number is within the affected range, the current system is affected by the vulnerability.
Users can run the following command to query the version of Ubuntu:
4 Vulnerability Protection
4.1 Version Upgrade
Ubuntu and Debian have released fixes for this vulnerability. Users can upgrade to the latest APT version to protect their systems.
For the security of the system, users are advised to disable HTTP redirect during the upgrade by running the following commands:
Users who cannot upgrade the APT online can download an appropriate offline installation package for local installation.
- Debian users can refer to the following link for the upgrade:
- Ubuntu users can refer to the following link for the upgrade:
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