# CVE-2023-30540: Chat poll data can still be queried from API after purging history in Nextcloud talk

> Users added to a conversation can access deleted chat poll data via the API, exposing previously purged information.

- **Severity:** Low 3.5 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 17 Apr 2023
- **Updated:** 3 Mar 2025
- **Also known as:** GHSA-c9hr-cq65-9mjw

## What is CVE-2023-30540?

CVE-2023-30540 is a low-severity vulnerability in nextcloud security-advisories, published on 17 Apr 2023. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.

### Official description

Nextcloud Talk is a chat, video & audio call extension for Nextcloud. In affected versions a user that was added later to a conversation can use this information to get access to data that was deleted before they were added to the conversation. This issue has been patched in version 15.0.5 and it is recommended that users upgrad to 15.0.5. There are no known workarounds for this issue.

Weakness: CWE-200 (Exposure of Sensitive Information to an Unauthorized Actor)

## Which versions are affected by CVE-2023-30540?

It affects 1 product.


Products: Nextcloud Talk.

## How do I fix CVE-2023-30540?

No fix has been published for CVE-2023-30540 yet. Limit exposure of the affected software until one is available.

## Is CVE-2023-30540 being exploited?

There is no known exploitation of CVE-2023-30540 in the wild and no public exploit code.

## Other vulnerabilities in nextcloud security-advisories

- [CVE-2020-8180](https://insights.sbomify.com/CVE-2020-8180/): Code injection in Nextcloud Talk (critical 9.9)
- [CVE-2021-32689](https://insights.sbomify.com/CVE-2021-32689/): Nextcloud Talk not properly disassociating users from chats after account deletion (high 8.1)
- [CVE-2023-39957](https://insights.sbomify.com/CVE-2023-39957/): Path traversal allows tricking the Talk Android app into writing files into it's root directory (high 7.2)
- [CVE-2021-32676](https://insights.sbomify.com/CVE-2021-32676/): Session Fixation in Nextcloud Talk (medium 6.5)
- [CVE-2021-39222](https://insights.sbomify.com/CVE-2021-39222/): XSS in Talk (medium 6.4)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-30540 and fix it if it is affected.

What it is: CVE-2023-30540 is a low-severity vulnerability in nextcloud security-advisories, published on 17 Apr 2023. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2023-30540 in the wild and no public exploit code.

Affected product: nextcloud security-advisories. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2023-30540/ (Markdown: https://insights.sbomify.com/CVE-2023-30540/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-30540
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-30540
- OSV: https://osv.dev/vulnerability/CVE-2023-30540

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-30540/
Summaries are generated and may contain mistakes; the official description above is the record.