---
title: "CVE-2019-3822\n    | Ubuntu"
description: Ubuntu is an open source software operating system that runs from the
  desktop, to the cloud, to all your internet connected things.
url: https://ubuntu.com/security/CVE-2019-3822?format=md
keywords: index, follow
---

# CVE-2019-3822

Publication date 6 February 2019

Last updated 25 August 2025

---

Ubuntu priority

**Medium**

[Why this priority?](https://ubuntu.com/security/cves/about#priority )

## Cvss 3 Severity Score

**9.8 · Critical**

[Score breakdown](https://ubuntu.com/security/CVE-2019-3822?format=md#impact-score)

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## Description

libcurl versions from 7.36.0 to before 7.64.0 are vulnerable to a
stack-based buffer overflow. The function creating an outgoing NTLM type-3
header (`lib/vauth/ntlm.c:Curl\_auth\_create\_ntlm\_type3\_message()`),
generates the request HTTP header contents based on previously received
data. The check that exists to prevent the local buffer from getting
overflowed is implemented wrongly (using unsigned math) and as such it does
not prevent the overflow from happening. This output data can grow larger
than the local buffer if very large 'nt response' data is extracted from a
previous NTLMv2 header provided by the malicious or broken HTTP server.
Such a 'large value' needs to be around 1000 bytes or more. The actual
payload data copied to the target buffer comes from the NTLMv2 type-2
response header.

[Read the notes from the security team](https://ubuntu.com/security/CVE-2019-3822?format=md#notes)

## Status

Show unmaintained releases

| Package | Ubuntu Release | Status |
| --- | --- | --- |
| curl | 18.10 cosmic | Fixed 7.61.0-1ubuntu2.3 |
| 18.04 LTS bionic | Fixed 7.58.0-2ubuntu3.6 |
| 16.04 LTS xenial | Fixed 7.47.0-1ubuntu2.12 |
| 14.04 LTS trusty | Not affected |

---

* [How can I get the fixes?](https://ubuntu.com/security/cves/about#security)
* [What do statuses mean?](https://ubuntu.com/security/cves/about#statuses)

## Notes

---

### [mdeslaur](https://launchpad.net/~mdeslaur)

affects libcurl 7.36.0 to and including 7.63.0

## Severity score breakdown

CVSS version:
CVSS v3.0

**Base score**

9.8 · Critical

* Base metrics

  | Parameter | Value |
  | --- | --- |
  | Attack vector | Network |
  | Attack complexity | Low |
  | Privileges required | None |
  | User interaction | None |
  | Scope | Unchanged |
  | Confidentiality impact | High |
  | Integrity impact | High |
  | Availability impact | High |
* Scores

  | Parameter | Value |
  | --- | --- |
  | Base score | 9.8 · Critical |
  | Exploitability score | - |
  | Impact score | - |

**Vector:** CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

## References

* [MITRE](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2019-3822)
* [NVD](https://nvd.nist.gov/vuln/detail/CVE-2019-3822)
* [Launchpad](https://launchpad.net/bugs/cve/CVE-2019-3822)
* [Debian](https://security-tracker.debian.org/tracker/CVE-2019-3822)

### Related Ubuntu Security Notices (USN)

+ [USN-3882-1](https://usn.ubuntu.com/USN-3882-1)
+ curl vulnerabilities
+ 6 February 2019

### Other references

* <https://curl.haxx.se/docs/CVE-2019-3822.html>
* <https://www.cve.org/CVERecord?id=CVE-2019-3822>