Description
click/install.py in click does not require files in package filesystem tarballs to start with ./ (dot slash), which allows remote attackers to install an alternate security policy and gain privileges via a crafted package, as demonstrated by the test.mmrow app for Ubuntu phone.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 14.04 LTS | click | 0.4.21.1ubuntu0.2 | USN-2771-1 |
Wolfi
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Wolfi rolling | py3.14-click | No fix yet | — |
Advisories 1
- USN-2771-1 click vulnerability Ubuntu Security Notices (USN) · Apr 22, 2026
References
- USN-2771-1 vendor-advisory
- 96386 vdb-entry
- http://bazaar.launchpad.net/~click-hackers/click/devel/revision/587
- https://bugs.launchpad.net/ubuntu/+source/click/+bug/1506467
- https://insights.ubuntu.com/2015/10/15/update-on-ubuntu-phone-security-issue/
- https://code.launchpad.net/~cjwatson/click/audit-missing-dot-slash/+merge/274554
- [oss-security] 20160112 Re: CVE Request: click mailing-list
- https://plus.google.com/+SzymonWaliczek/posts/3jbG2uiAniF