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Fencer Vulns
critical 9.8

CVE-2020-27853 json

Wire before 2020-10-16 allows remote attackers to cause a denial of service (application crash) or possibly execute arbitrary code via a fo…

published 2020-10-27 6 y ago modified 2026-06-17 4 mo ago also EUVD-2020-20346

cvss
9.8
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
3.9%
EPSS 3.9% chance of exploitation in 30 days, percentile 90%
public exploits
0
none known

Summary

Wire before 2020-10-16 allows remote attackers to cause a denial of service (application crash) or possibly execute arbitrary code via a format string. This affects Wire AVS (Audio, Video, and Signaling) 5.3 through 6.x before 6.4, the Wire Secure Messenger application before 3.49.918 for Android, and the Wire Secure Messenger application before 3.61 for iOS. This occurs via the value parameter to sdp_media_set_lattr in peerflow/sdp.c.

Patch / fix

  • wire wire 3.21.2936, 3.21.3932, 3.21.3959
  • wire wire_-_audio,_video,_and_signaling 6.4
  • wire wire_secure_messenger 3.49.918, 3.61

Exploit prediction

3.94% chance of exploitation in the next 30 days, higher than 90% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/wireapp/wire-audio-video-signaling/issues/23#issuecomment-710075689 referenced PoC, tagged "exploit" by a source, unverified
  • github.security.telekom.com http://github.security.telekom.com/2020/11/wire-secure-messenger-format-string-vulnerability.html referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 7.5 AV:N/AC:L/Au:N/C:P/I:P/A:P

Classification

Weakness
  • CWE-134 Use of Externally-Controlled Format String

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.