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Fencer Vulns
critical 9.8

CVE-2016-2851 in the critical feed json

Integer overflow in proto.c in libotr before 4.1.1 on 64-bit platforms allows remote attackers to cause a denial of service (memory corrupt…

published 2016-04-07 10 y ago modified 2026-06-17 4 mo ago also EUVD-2016-3924

cvss
9.8
version 3.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
24.3%
EPSS 24.3% chance of exploitation in 30 days, percentile 97%
public exploits
1
Exploit-DB

Summary

Integer overflow in proto.c in libotr before 4.1.1 on 64-bit platforms allows remote attackers to cause a denial of service (memory corruption and application crash) or execute arbitrary code via a series of large OTR messages, which triggers a heap-based buffer overflow.

Patch / fix

  • libotr Debian 14, Debian 13, Debian 12 4.1.1-1

debian advisories DEBIAN-CVE-2016-2851

  • libotr Ubuntu 14.04 LTS 4.0.0-2.2ubuntu1.1

ubuntu advisories UBUNTU-CVE-2016-2851

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • libotr SLES for SAP 11 SP4, SLES 11 SP4, SLED 11 SP4 +1 more 3.2.0-10.5.1
  • libotr SLES for SAP 12 SP1, SLES for SAP 12, SLES 12 SP1 +5 more 4.0.0-9.1

suse advisories SUSE-SU-2016:0706-1SUSE-SU-2016:0707-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2016-2851 updated cvss 6.8

libotr: Integer overflow when receiving messages bigger than 4GB

  • Red Hat All currently supported Red Hat products
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Timeline

  1. First public exploit (EDB-39550)
  2. Published

Exploit prediction

24.28% chance of exploitation in the next 30 days, higher than 97% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • EDB-39550 libotr 4.1.0 - Memory Corruption dos, 2016-03-10
  • seclists.org http://seclists.org/fulldisclosure/2016/Mar/21 referenced PoC, tagged "exploit" by a source, unverified
  • x41-dsec.de https://www.x41-dsec.de/lab/advisories/x41-2016-001-libotr/ referenced PoC, tagged "exploit" by a source, unverified
  • lists.cypherpunks.ca https://lists.cypherpunks.ca/pipermail/otr-users/2016-March/002581.html referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.0 9.8 CVSS:3.0/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-119 Improper Restriction of Operations within the Bounds of a Memory Buffer

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.