Description
An issue was discovered in Prosody before 0.11.9. It does not use a constant-time algorithm for comparing certain secret strings when running under Lua 5.2 or later. This can potentially be used in a timing attack to reveal the contents of secret strings to an attacker.
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 |
| Debian 9 | prosody | 0.9.12-2+deb9u3 | DLA-2687-1 |
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 | — |
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 2
- DSA-4916-1 prosody - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-2687-1 prosody - security update Debian Security (DSA / DLA) · Mar 9, 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
- [debian-lts-announce] 20210616 [SECURITY] [DLA 2687-1] prosody security update mailing-list
- [debian-lts-announce] 20210619 [SECURITY] [DLA 2687-2] prosody regression update mailing-list