---
title: "CVE-2018-10657\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-2018-10657?format=md
keywords: index, follow
---

# CVE-2018-10657

Publication date 2 May 2018

Last updated 25 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-2018-10657?format=md#impact-score)

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## Description

Matrix Synapse before 0.28.1 is prone to a denial of service flaw where
malicious events injected with depth = 2^63 - 1 render rooms unusable,
related to federation/federation\_base.py and handlers/message.py, as
exploited in the wild in April 2018.

[Read the notes from the security team](https://ubuntu.com/security/CVE-2018-10657?format=md#notes)

## Status

Show unmaintained releases

| Package | Ubuntu Release | Status |
| --- | --- | --- |
| matrix-synapse | 23.04 lunar | Fixed 0.28.1+dfsg-1 |
| 22.10 kinetic | Fixed 0.28.1+dfsg-1 |
| 22.04 LTS jammy | Fixed 0.28.1+dfsg-1 |
| 21.10 impish | Fixed 0.28.1+dfsg-1 |
| 21.04 hirsute | Fixed 0.28.1+dfsg-1 |
| 20.10 groovy | Fixed 0.28.1+dfsg-1 |
| 20.04 LTS focal | Fixed 0.28.1+dfsg-1 |
| 19.10 eoan | Fixed 0.28.1+dfsg-1 |
| 19.04 disco | Fixed 0.28.1+dfsg-1 |
| 18.10 cosmic | Fixed 0.28.1+dfsg-1 |
| 18.04 LTS bionic | Fixed 0.24.0+dfsg-1ubuntu0.1~esm1  Ubuntu Pro |
| 17.10 artful | Ignored end of life |
| 16.04 LTS xenial | Not in release |
| 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)
* [Patch details](https://ubuntu.com/security/CVE-2018-10657?format=md#patch-details)

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## Notes

---

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

code is quite different in bionic and artful versus patch.

### Patch details

For informational purposes only. We recommend not to cherry-pick updates. [How can I get the fixes?](https://ubuntu.com/security/cves/about#security)

| Package | Patch details |
| --- | --- |
| matrix-synapse | * Upstream:   [33f469b](https://github.com/matrix-org/synapse/commit/33f469ba19586bbafa0cf2c7d7c35463bdab87eb) |

## 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 | None |
  | Integrity impact | None |
  | Availability impact | High |
* Scores

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

**Vector:** CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

## References

* [MITRE](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-10657)
* [NVD](https://nvd.nist.gov/vuln/detail/CVE-2018-10657)
* [Launchpad](https://launchpad.net/bugs/cve/CVE-2018-10657)
* [Debian](https://security-tracker.debian.org/tracker/CVE-2018-10657)

### Related Ubuntu Security Notices (USN)

+ [USN-6076-1](https://usn.ubuntu.com/USN-6076-1)
+ Synapse vulnerabilities
+ 16 May 2023

### Other references

* <https://github.com/matrix-org/synapse/commit/33f469ba19586bbafa0cf2c7d7c35463bdab87eb>
* <https://matrix.org/blog/2018/05/01/security-update-synapse-0-28-1/>
* <https://docs.google.com/document/d/1I3fi2S-XnpO45qrpCsowZv8P8dHcNZ4fsBsbOW7KABI/edit#heading=h.fj95ykuss7s1>
* <https://www.cve.org/CVERecord?id=CVE-2018-10657>