How severe is GHSA-x5q3-c8rm-w787?

GHSA-x5q3-c8rm-w787 has a CVSS score of 8.8/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by GHSA-x5q3-c8rm-w787?

GHSA-x5q3-c8rm-w787 affects the following packages: github.com/ubuntu/authd (Go), github.com/ubuntu/authd (Go). Ecosystems affected: Go.

How do I fix GHSA-x5q3-c8rm-w787?

Update github.com/ubuntu/authd to 0.0.0-20240930103526-63e527496b01 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-x5q3-c8rm-w787 is resolved across your whole dependency graph.

How do I detect GHSA-x5q3-c8rm-w787 in my Go dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/ubuntu/authd. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

How do I mitigate GHSA-x5q3-c8rm-w787 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

How does O3 Security protect against GHSA-x5q3-c8rm-w787?

O3 pinpoints whether GHSA-x5q3-c8rm-w787 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is GHSA-x5q3-c8rm-w787 actively exploited in the wild?

No public exploit code has been indexed for GHSA-x5q3-c8rm-w787 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

When was GHSA-x5q3-c8rm-w787 published, and has it been updated?

GHSA-x5q3-c8rm-w787 was published on October 3, 2024 and was last updated on January 21, 2025. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐹 Go

GHSA-x5q3-c8rm-w787

HIGH

GHSA-x5q3-c8rm-w787 is a high-severity (CVSS 8.8) vulnerability in github.com/ubuntu/authd. O3 Security confirms whether GHSA-x5q3-c8rm-w787 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.

PAM module may allow accessing with the credentials of another user

Also known asCVE-2024-9313GO-2024-3181

Published

Oct 3, 2024

Updated

Jan 21, 2025

Affected

2 pkgs

Patched

2 / 2

Exploits

None indexed

Blast Radius

2 pkgs affected

🐹github.com/ubuntu/authd🐹github.com/ubuntu/authd

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.

Description

Authd PAM module up to version 0.3.4 can allow broker-managed users to impersonate any other user managed by the same broker and perform any PAM operation with it, including authenticating as them.

This is possible using tools such as su, sudo or ssh (and potentially others) that, so far, do not ensure that the PAM user at the end of the transaction is matching the one who initiated the transaction.

Authd 0.3.5 fixes this by not allowing changing the user unless it was never set before in the PAM stack.

su version that will include https://github.com/util-linux/util-linux/pull/3206 will not be affected ssh version that will include https://github.com/openssh/openssh-portable/pull/521 will not be affected sudo version that will include https://github.com/sudo-project/sudo/pull/412 will not be affected login not affected passwd not affected

<details> <summary>Old report</summary>

Summary

An user can access as another user using its own credentials

Details

I feel we’ve a security issue that is due to the fact that we allow changing the user in the cases in which that’s already provided by PAM, I’ve not tested this using the entra-id broker but it’s reproducible with the example one, but unless I’m missing something it should be independent from the broker in use.

Basically, by going to the user selection page we allow to login as any user by entering the use own credentials.

See for example: https://asciinema.org/a/VIcjpDImomaGu0wxsJJxNdmlf or https://asciinema.org/a/CV3D1gaEhn2yclqSMKCnifYPo

Basically it’s possible to logging in as user1 using the credentials of user2 or user3.

The issue doesn’t affect login or passwd, but it does affect su and sshd, since in both cases they don’t check if the PAM_USER changed before the final authentication.

Now, while those tools should likely be fixed to only read the PAM_USER once pam gave them the final ok, I think authd should not allow changing the user at all when it has been provided by PAM.

</details>

Affected Packages

2 total 2 fixed

Ecosystem	Package	Vulnerable range	Fix
🐹Go	`github.com/ubuntu/authd`	all versions	0.0.0-20240930103526-63e527496b01
🐹Go	`github.com/ubuntu/authd`	≥ 0.1.0&&< 0.3.5	0.3.5

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/ubuntu/authd. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update github.com/ubuntu/authd to 0.0.0-20240930103526-63e527496b01 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-x5q3-c8rm-w787 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-x5q3-c8rm-w787 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to GHSA-x5q3-c8rm-w787. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

Authd PAM module up to version 0.3.4 can allow broker-managed users to impersonate any other user managed by the same broker and perform any PAM operation with it, including authenticating as them. This is possible using tools such as `su`, `sudo` or `ssh` (and potentially others) that, so far, do not ensure that the PAM user at the end of the transaction is matching the one who initiated the transaction. Authd 0.3.5 fixes this by not allowing changing the user unless it was never set before in the PAM stack. `su` version that will include https://github.com/util-linux/util-linux/pull/3206

O3 Security · Impact-Aware SCA

Is GHSA-x5q3-c8rm-w787 in your dependencies?

O3 detects GHSA-x5q3-c8rm-w787 across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

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