# CVE-2019-17455: Memory corruption in n/a

> A stack-based buffer over-read in Libntlm allows attackers to cause denial of service or disclose sensitive information via crafted NTLM requests.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/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:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 10 Oct 2019
- **Updated:** 5 Aug 2024
- **Also known as:** AZL-7266, DEBIAN-CVE-2019-17455, DLA-2207-1, DLA-2831-1, GHSA-m8c7-4hj3-f3m6, MGASA-2020-0219, UBUNTU-CVE-2019-17455, USN-5108-1, USN-5108-2, openSUSE-SU-2020:0806-1, openSUSE-SU-2020:0816-1, openSUSE-SU-2024:10963-1

## What is CVE-2019-17455?

CVE-2019-17455 is a critical memory corruption vulnerability in Canonical Ubuntu Linux, published on 10 Oct 2019. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Libntlm through 1.5 relies on a fixed buffer size for tSmbNtlmAuthRequest, tSmbNtlmAuthChallenge, and tSmbNtlmAuthResponse read and write operations, as demonstrated by a stack-based buffer over-read in buildSmbNtlmAuthRequest in smbutil.c for a crafted NTLM request.

Weakness: CWE-125 (Out-of-bounds Read)

## Which versions are affected by CVE-2019-17455?

It affects 6 products.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `libntlm` | SUSE:Package Hub 15 SP1 | All versions | 1.6-bp151.4.3.1 |
| `libntlm` | openSUSE:Leap 15.1 | All versions | 1.6-lp151.3.3.1 |

Products: Canonical Ubuntu Linux, Debian Debian Linux, Fedoraproject Fedora, Nongnu Libntlm, Opensuse Backports Sle, Opensuse Leap.

## How do I fix CVE-2019-17455?

Upgrade to a fixed version.

## Is CVE-2019-17455 being exploited?

There is no known exploitation of CVE-2019-17455 in the wild and no public exploit code.

## Other vulnerabilities in Canonical Ubuntu Linux

- [CVE-2020-11651](https://insights.sbomify.com/CVE-2020-11651/): SaltStack Salt Authentication Bypass (critical 9.8, exploited in the wild)
- [CVE-2020-7247](https://insights.sbomify.com/CVE-2020-7247/): OpenSMTPD Remote Code Execution (critical 9.8, exploited in the wild)
- [CVE-2019-16928](https://insights.sbomify.com/CVE-2019-16928/): Exim Out-of-bounds Write (critical 9.8, exploited in the wild)
- [CVE-2018-6789](https://insights.sbomify.com/CVE-2018-6789/): Exim Buffer Overflow (critical 9.8, exploited in the wild)
- [CVE-2015-2590](https://insights.sbomify.com/CVE-2015-2590/): Oracle Java SE and Java SE Embedded Remote Code Execution (critical 9.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2019-17455 and fix it if it is affected.

What it is: CVE-2019-17455 is a critical memory corruption vulnerability in Canonical Ubuntu Linux, published on 10 Oct 2019. 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-2019-17455 in the wild and no public exploit code.

Affected product: Canonical Ubuntu Linux. 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-2019-17455/ (Markdown: https://insights.sbomify.com/CVE-2019-17455/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2019-17455
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2019-17455
- OSV: https://osv.dev/vulnerability/CVE-2019-17455

---
From sbomify Insights: https://insights.sbomify.com/CVE-2019-17455/
Summaries are generated and may contain mistakes; the official description above is the record.