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Fencer Vulns
medium 5.3

CVE-2021-41119 json

DoS vulnerabiliity in wire-server json parser

published 2022-04-13 4 y ago modified 2026-06-17 4 mo ago also EUVD-2021-28250

cvss
5.3
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
1.4%
EPSS 1.4% chance of exploitation in 30 days, percentile 71%
public exploits
0
none known

Summary

Wire-server is the system server for the wire back-end services. Releases prior to v2022-03-01 are subject to a denial of service attack via a crafted object causing a hash collision. This collision causes the server to spend at least quadratic time parsing it which can lead to a denial of service for a heavily used server. The issue has been fixed in wire-server 2022-03-01 and is already deployed on all Wire managed services. On premise instances of wire-server need to be updated to 2022-03-01, so that their backends are no longer affected. There are no known workarounds for this issue.

Patch / fix

  • wire wire-server 2022-03-01

CISA SSVC

Exploitation
Proof of concept is public
Automatable
yes
Technical impact
partial
Assessed
18 mo ago

Exploit prediction

1.36% chance of exploitation in the next 30 days, higher than 71% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • cs-syd.eu https://cs-syd.eu/posts/2021-09-11-json-vulnerability referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 5.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
NVD 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD 2.0 5.0 AV:N/AC:L/Au:N/C:N/I:N/A:P

Affected products

  • wireapp wire-server

Classification

Weakness
  • CWE-400 Uncontrolled Resource Consumption

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.