Malicious code was discovered in the upstream tarballs of xz, starting with version 5.6.0. Through a series of complex obfuscations, the liblzma build process extracts a prebuilt object file from a disguised test file existing in the source code, which is then used to modify specific functions in the liblzma code. This results in a modified liblzma library that can be used by any software linked against this library, intercepting and modifying the data interaction with this library.
{
"priority_reason": "Results in a backdoor in sshd",
"availability": "No subscription required",
"binaries": [
{
"binary_version": "5.2.4-1ubuntu1.1",
"binary_name": "liblzma-dev"
},
{
"binary_version": "5.2.4-1ubuntu1.1",
"binary_name": "liblzma-doc"
},
{
"binary_version": "5.2.4-1ubuntu1.1",
"binary_name": "liblzma5"
},
{
"binary_version": "5.2.4-1ubuntu1.1",
"binary_name": "liblzma5-dbgsym"
},
{
"binary_version": "5.2.4-1ubuntu1.1",
"binary_name": "xz-utils"
},
{
"binary_version": "5.2.4-1ubuntu1.1",
"binary_name": "xz-utils-dbgsym"
},
{
"binary_version": "5.2.4-1ubuntu1.1",
"binary_name": "xzdec"
},
{
"binary_version": "5.2.4-1ubuntu1.1",
"binary_name": "xzdec-dbgsym"
}
]
}
{
"priority_reason": "Results in a backdoor in sshd",
"availability": "No subscription required",
"binaries": [
{
"binary_version": "5.2.5-2ubuntu1",
"binary_name": "liblzma-dev"
},
{
"binary_version": "5.2.5-2ubuntu1",
"binary_name": "liblzma-doc"
},
{
"binary_version": "5.2.5-2ubuntu1",
"binary_name": "liblzma5"
},
{
"binary_version": "5.2.5-2ubuntu1",
"binary_name": "liblzma5-dbgsym"
},
{
"binary_version": "5.2.5-2ubuntu1",
"binary_name": "xz-utils"
},
{
"binary_version": "5.2.5-2ubuntu1",
"binary_name": "xz-utils-dbgsym"
},
{
"binary_version": "5.2.5-2ubuntu1",
"binary_name": "xzdec"
},
{
"binary_version": "5.2.5-2ubuntu1",
"binary_name": "xzdec-dbgsym"
}
]
}
{
"priority_reason": "Results in a backdoor in sshd",
"availability": "No subscription required",
"binaries": [
{
"binary_version": "5.4.5-0.3",
"binary_name": "liblzma-dev"
},
{
"binary_version": "5.4.5-0.3",
"binary_name": "liblzma-doc"
},
{
"binary_version": "5.4.5-0.3",
"binary_name": "liblzma5"
},
{
"binary_version": "5.4.5-0.3",
"binary_name": "liblzma5-dbgsym"
},
{
"binary_version": "5.4.5-0.3",
"binary_name": "xz-utils"
},
{
"binary_version": "5.4.5-0.3",
"binary_name": "xz-utils-dbgsym"
},
{
"binary_version": "5.4.5-0.3",
"binary_name": "xzdec"
},
{
"binary_version": "5.4.5-0.3",
"binary_name": "xzdec-dbgsym"
}
]
}