Further restrict API names character set and prevent shell expansion#2827
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Further restrict API names character set and prevent shell expansion#2827
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Since some of those names may be passed to a shell either on the client or server side, let's avoid getting into potential variable expansions. Signed-off-by: Stéphane Graber <[email protected]> Reported-by: Rory McNamara <[email protected]>
Signed-off-by: Stéphane Graber <[email protected]> Suggested-by: Rory McNamara <[email protected]>
This avoids potential shell expansion of the strings should some special characters manage to make it through. Signed-off-by: Rory McNamara <[email protected]>
This was referenced Jan 26, 2026
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Based on lxc/incus#2827 Related to https://github.com/lxc/incus/security/advisories/GHSA-8h3p-58qv-8p53 From @stgraber : > The LXC driver generates an LXC config file which includes some LXC hooks. > Those get run through a shell and may therefore get expanded if special characters are allowed. > > Some care was taken around that by using strconv.Quote, but this only leads to double quoted rather than single quoted strings (equivalent to "%q" in fmt.Sprintf) when for something exposed to a shell, we really want single quoted strings. > > To address potential issues, this branch: > > - Introduces a new util.SingleQuote function (sadly strconv doesn't provide this directly) > - Makes use of util.SingleQuote where strconv.Quote was previously used > > This issue came out from security research work by @rmcnamara-snyk but as any exploitation of this requires full admin privileges on Incus, it didn't qualify as a security issue.
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The LXC driver generates an LXC config file which includes some LXC hooks.
Those get run through a shell and may therefore get expanded if special characters are allowed.
Some care was taken around that by using
strconv.Quote, but this only leads to double quoted rather than single quoted strings (equivalent to"%q"in fmt.Sprintf) when for something exposed to a shell, we really want single quoted strings.To address potential issues, this branch:
$anywhere in the Incus API object namesutil.SingleQuotefunction (sadlystrconvdoesn't provide this directlyutil.SingleQuotewherestrconv.Quotewas previously usedThis issue came out from security research work by @rmcnamara-snyk but as any exploitation of this requires full admin privileges on Incus, it didn't qualify as a security issue.