# CVE-2018-15543: Auth bypass in n/a

> Attackers can bypass biometric authentication in the Telegram Android app by manipulating callback methods, allowing unauthorized access.

- **Severity:** Medium 6.8 (`CVSS:3.0/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 9 Oct 2018
- **Updated:** 14 Nov 2024
- **Also known as:** GHSA-4cfw-g6m2-82xj

## What is CVE-2018-15543?

CVE-2018-15543 is a medium-severity authentication bypass vulnerability in n/a, published on 9 Oct 2018. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

An issue was discovered in the org.telegram.messenger application 4.8.11 for Android. The FingerprintManager class for Biometric validation allows authentication bypass through the callback method from onAuthenticationFailed to onAuthenticationSucceeded with null, because the fingerprint API in conjunction with the Android keyGenerator class is not implemented. In other words, an attacker could authenticate with an arbitrary fingerprint.  NOTE: the vendor indicates that this is not an attack of interest within the context of their threat model, which excludes Android devices on which rooting has occurred

Weakness: CWE-287 (Improper Authentication)

## Which versions are affected by CVE-2018-15543?

It affects 1 product.


Products: Telegram Telegram.

## How do I fix CVE-2018-15543?

No fix has been published for CVE-2018-15543 yet. Limit exposure of the affected software until one is available.

## Is CVE-2018-15543 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2018-15543 exists.

## Other vulnerabilities in n/a

- [CVE-2019-10044](https://insights.sbomify.com/CVE-2019-10044/): Other in n/a (high 8.8)
- [CVE-2018-20436](https://insights.sbomify.com/CVE-2018-20436/): Server-side request forgery in n/a (high 8.1)
- [CVE-2024-7014](https://insights.sbomify.com/CVE-2024-7014/): Improper multimedia file attachment validation in Telegram for Android app (high 7.1)
- [CVE-2021-31320](https://insights.sbomify.com/CVE-2021-31320/): Memory corruption in n/a (high 7.1)
- [CVE-2021-31321](https://insights.sbomify.com/CVE-2021-31321/): Memory corruption in n/a (high 7.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2018-15543 and fix it if it is affected.

What it is: CVE-2018-15543 is a medium-severity authentication bypass vulnerability in n/a, published on 9 Oct 2018. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2018-15543 exists.

Affected product: n/a. 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-2018-15543/ (Markdown: https://insights.sbomify.com/CVE-2018-15543/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2018-15543
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-15543
- OSV: https://osv.dev/vulnerability/CVE-2018-15543

---
From sbomify Insights: https://insights.sbomify.com/CVE-2018-15543/
Summaries are generated and may contain mistakes; the official description above is the record.