Description
An issue was discovered in Prosody before 0.11.9. The undocumented dialback_without_dialback option in mod_dialback enables an experimental feature for server-to-server authentication. It does not correctly authenticate remote server certificates, allowing a remote server to impersonate another server (when this option is enabled).
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | prosody | 0.11.9-1 | — |
| Debian 13 | prosody | 0.11.9-1 | — |
| Debian 12 | prosody | 0.11.9-1 | — |
| Debian 10 | prosody | 0.11.2-1+deb10u1 | DSA-4916-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 22.04 LTS | prosody | No fix yet | — |
| Ubuntu 20.04 LTS | prosody | No fix yet | — |
| Ubuntu 16.04 LTS | prosody | No fix yet | — |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 18.04 LTS | prosody | No fix yet | — |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SUSE Package Hub 15 SP2 | prosody | 0.11.9-bp152.2.3.1 | openSUSE-SU-2021:0751-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | prosody | 0.11.10-1.2 | openSUSE-SU-2024:11197-1 |
| openSUSE Leap 15.2 | prosody | 0.11.9-lp152.2.3.1 | openSUSE-SU-2021:0728-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | prosody | 0.11.9-r0 | — |
| Alpine v3.23 | prosody | 0.11.9-r0 | — |
| Alpine v3.22 | prosody | 0.11.9-r0 | — |
| Alpine v3.21 | prosody | 0.11.9-r0 | — |
| Alpine v3.20 | prosody | 0.11.9-r0 | — |
Show 8 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.19 | prosody | 0.11.9-r0 | — |
| Alpine v3.18 | prosody | 0.11.9-r0 | — |
| Alpine v3.17 | prosody | 0.11.9-r0 | — |
| Alpine v3.16 | prosody | 0.11.9-r0 | — |
| Alpine v3.15 | prosody | 0.11.9-r0 | — |
| Alpine v3.14 | prosody | 0.11.9-r0 | — |
| Alpine v3.13 | prosody | 0.11.9-r0 | — |
| Alpine v3.12 | prosody | 0.11.9-r0 | — |
Advisories 4
- DSA-4916-1 prosody - security update Debian Security (DSA / DLA) · Mar 9, 2026
- openSUSE-SU-2021:0728-1 Security update for prosody SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2021:0751-1 Security update for prosody SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2024:11197-1 prosody-0.11.10-1.2 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
References
- https://blog.prosody.im/prosody-0.11.9-released/
- [oss-security] 20210513 Prosody XMPP server advisory 2021-05-12 (multiple vulnerabilities) mailing-list
- [oss-security] 20210514 Re: Prosody XMPP server advisory 2021-05-12 (multiple vulnerabilities) mailing-list
- DSA-4916 vendor-advisory
- FEDORA-2021-b5d8c6d086 vendor-advisory
- FEDORA-2021-a33f6e36e1 vendor-advisory
- FEDORA-2021-498be8f560 vendor-advisory
- https://security.gentoo.org/glsa/202105-15