# CVE-2018-10240: Weak cryptography in n/a

> Attackers can brute-force low-entropy session tokens to hijack user sessions in SolarWinds Serv-U MFT.

- **Severity:** High 7.3 (`CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 16 May 2018
- **Updated:** 5 Aug 2024
- **Also known as:** GHSA-hw6q-c5xp-mh35

## What is CVE-2018-10240?

CVE-2018-10240 is a high-severity vulnerability in Solarwinds Serv-U, published on 16 May 2018. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

SolarWinds Serv-U MFT before 15.1.6 HFv1 assigns authenticated users a low-entropy session token that can be included in requests to the application as a URL parameter in lieu of a session cookie. This session token's value can be brute-forced by an attacker to obtain the corresponding session cookie and hijack the user's session.

Weakness: CWE-331 (Insufficient Entropy)

## Which versions are affected by CVE-2018-10240?

It affects 1 product.


Products: Solarwinds Serv-U.

## How do I fix CVE-2018-10240?

No fix has been published for CVE-2018-10240 yet. Limit exposure of the affected software until one is available.

## Is CVE-2018-10240 being exploited?

There is no known exploitation of CVE-2018-10240 in the wild and no public exploit code.

## Other vulnerabilities in Solarwinds Serv-U

- [CVE-2021-35211](https://insights.sbomify.com/CVE-2021-35211/): SolarWinds Serv-U Remote Code Execution (critical 9.0, exploited in the wild)
- [CVE-2024-28995](https://insights.sbomify.com/CVE-2024-28995/): SolarWinds Serv-U Path Traversal Vulnerability (high 8.6, exploited in the wild)
- [CVE-2026-28318](https://insights.sbomify.com/CVE-2026-28318/): SolarWinds Serv-U Uncontrolled Resource Consumption (high 7.5, exploited in the wild)
- [CVE-2021-35247](https://insights.sbomify.com/CVE-2021-35247/): SolarWinds Serv-U Improper Input Validation (medium 4.3, exploited in the wild)
- [CVE-2020-35481](https://insights.sbomify.com/CVE-2020-35481/): Code injection in n/a (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2018-10240 and fix it if it is affected.

What it is: CVE-2018-10240 is a high-severity vulnerability in Solarwinds Serv-U, published on 16 May 2018. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2018-10240 in the wild and no public exploit code.

Affected product: Solarwinds Serv-U. 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-2018-10240/ (Markdown: https://insights.sbomify.com/CVE-2018-10240/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2018-10240
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-10240
- OSV: https://osv.dev/vulnerability/CVE-2018-10240

---
From sbomify Insights: https://insights.sbomify.com/CVE-2018-10240/
Summaries are generated and may contain mistakes; the official description above is the record.