# CVE-2024-45300: Bypassing promo code limitations with race conditions

> Attackers can bypass promo code usage limits via race conditions, allowing unauthorized multiple uses of discount coupons in alf.io.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 6 Sep 2024
- **Updated:** 6 Sep 2024
- **Also known as:** GHSA-67jg-m6f3-473g

## What is CVE-2024-45300?

CVE-2024-45300 is a high-severity vulnerability in alfio-event alf.io, published on 6 Sep 2024. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

alf.io is an open source ticket reservation system for conferences, trade shows, workshops, and meetups. Prior to version 2.0-M5, a race condition allows the user to bypass the limit on the number of promo codes and use the discount coupon multiple times. In "alf.io", an event organizer can apply price discounts by using promo codes to your events. The organizer can limit the number of promo codes that will be used for this, but the time-gap between checking the number of codes and restricting the use of the codes allows a threat actor to bypass the promo code limit. Version 2.0-M5 fixes this issue.

Weakness: CWE-362 (Concurrent Execution using Shared Resource with Improper Synchronization)

## Which versions are affected by CVE-2024-45300?

It affects 1 product.


Products: Alf Alf.

## How do I fix CVE-2024-45300?

No fix has been published for CVE-2024-45300 yet. Limit exposure of the affected software until one is available.

## Is CVE-2024-45300 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2024-45300 exists.

## Other vulnerabilities in alfio-event alf.io

- [CVE-2023-2259](https://insights.sbomify.com/CVE-2023-2259/): Improper Neutralization of Special Elements Used in a Template Engine in alfio-event/alf.io (critical 9.1)
- [CVE-2024-25635](https://insights.sbomify.com/CVE-2024-25635/): IDOR Vulnerability: Allowing Organization Owner to view the other Organizations API KEY and USERS (high 8.8)
- [CVE-2023-2258](https://insights.sbomify.com/CVE-2023-2258/): Improper Neutralization of Formula Elements in a CSV File in alfio-event/alf.io (high 8.8)
- [CVE-2023-2260](https://insights.sbomify.com/CVE-2023-2260/): Authorization Bypass Through User-Controlled Key in alfio-event/alf.io (high 8.8)
- [CVE-2026-35482](https://insights.sbomify.com/CVE-2026-35482/): alf.io has an Authenticated RCE via Extension Script Sandbox Escape (high 8.0)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2024-45300 and fix it if it is affected.

What it is: CVE-2024-45300 is a high-severity vulnerability in alfio-event alf.io, published on 6 Sep 2024. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2024-45300 exists.

Affected product: alfio-event alf.io. 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-2024-45300/ (Markdown: https://insights.sbomify.com/CVE-2024-45300/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-45300
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-45300
- OSV: https://osv.dev/vulnerability/CVE-2024-45300

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-45300/
Summaries are generated and may contain mistakes; the official description above is the record.