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.
{
"availability": "No subscription required",
"binaries": [
{
"binary_name": "liblzma-dev",
"binary_version": "5.2.4-1ubuntu1.1"
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{
"binary_name": "liblzma-doc",
"binary_version": "5.2.4-1ubuntu1.1"
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{
"binary_name": "liblzma5",
"binary_version": "5.2.4-1ubuntu1.1"
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{
"binary_name": "liblzma5-dbgsym",
"binary_version": "5.2.4-1ubuntu1.1"
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{
"binary_name": "xz-utils",
"binary_version": "5.2.4-1ubuntu1.1"
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{
"binary_name": "xz-utils-dbgsym",
"binary_version": "5.2.4-1ubuntu1.1"
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{
"binary_name": "xzdec",
"binary_version": "5.2.4-1ubuntu1.1"
},
{
"binary_name": "xzdec-dbgsym",
"binary_version": "5.2.4-1ubuntu1.1"
}
],
"priority_reason": "Results in a backdoor in sshd"
}
{
"availability": "No subscription required",
"binaries": [
{
"binary_name": "liblzma-dev",
"binary_version": "5.2.5-2ubuntu1"
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{
"binary_name": "liblzma-doc",
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"binary_name": "liblzma5",
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"binary_version": "5.2.5-2ubuntu1"
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{
"binary_name": "xz-utils",
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"binary_version": "5.2.5-2ubuntu1"
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{
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{
"binary_name": "xzdec-dbgsym",
"binary_version": "5.2.5-2ubuntu1"
}
],
"priority_reason": "Results in a backdoor in sshd"
}
{
"availability": "No subscription required",
"binaries": [
{
"binary_name": "liblzma-dev",
"binary_version": "5.4.5-0.3"
},
{
"binary_name": "liblzma-doc",
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{
"binary_name": "liblzma5",
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"binary_name": "xzdec",
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{
"binary_name": "xzdec-dbgsym",
"binary_version": "5.4.5-0.3"
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"priority_reason": "Results in a backdoor in sshd"
}