---
title: "CVE-2020-1899\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-2020-1899?format=md
keywords: index, follow
---

# CVE-2020-1899

Publication date 11 March 2021

Last updated 26 August 2025

---

Ubuntu priority

**Medium**

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

## Cvss 3 Severity Score

**7.5 · High**

[Score breakdown](https://ubuntu.com/security/CVE-2020-1899?format=md#impact-score)

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## Description

The unserialize() function supported a type code, "S", which was meant to
be supported only for APC serialization. This type code allowed arbitrary
memory addresses to be accessed as if they were static StringData objects.
This issue affected HHVM prior to v4.32.3, between versions 4.33.0 and
4.56.0, 4.57.0, 4.58.0, 4.58.1, 4.59.0, 4.60.0, 4.61.0, 4.62.0.

## Status

Show unmaintained releases

| Package | Ubuntu Release | Status |
| --- | --- | --- |
| hhvm | 26.04 LTS resolute | Not in release |
| 25.10 questing | Not in release |
| 25.04 plucky | Not in release |
| 24.10 oracular | Not in release |
| 24.04 LTS noble | Not in release |
| 23.10 mantic | Not in release |
| 23.04 lunar | Not in release |
| 22.10 kinetic | Not in release |
| 22.04 LTS jammy | Not in release |
| 21.10 impish | Not in release |
| 21.04 hirsute | Not in release |
| 20.10 groovy | Not in release |
| 20.04 LTS focal | Not in release |
| 18.04 LTS bionic | Needs evaluation |
| 16.04 LTS xenial | Needs evaluation |
| 14.04 LTS trusty | Not in release |

---

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

## Severity score breakdown

CVSS version:
CVSS v3.0

**Base score**

7.5 · High

* Base metrics

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

  | Parameter | Value |
  | --- | --- |
  | Base score | 7.5 · High |
  | Exploitability score | - |
  | Impact score | - |

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

## References

* [MITRE](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-1899)
* [NVD](https://nvd.nist.gov/vuln/detail/CVE-2020-1899)
* [Launchpad](https://launchpad.net/bugs/cve/CVE-2020-1899)
* [Debian](https://security-tracker.debian.org/tracker/CVE-2020-1899)

### Other references

* <https://github.com/facebook/hhvm/commit/1107228a5128d3ca1c4add8ac1635d933cbbe2e9>
* <https://hhvm.com/blog/2020/06/30/security-update.html>
* <https://www.cve.org/CVERecord?id=CVE-2020-1899>