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Fencer Vulns
medium 6.5

CVE-2020-8244 json

Remote Memory Exposure in bl

published 2020-08-30 6 y ago modified 2026-06-17 4 mo ago also GHSA-pp7h-53gx-mx7r , EUVD-2020-1218

cvss
6.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
2.1%
EPSS 2.1% chance of exploitation in 30 days, percentile 81%
public exploits
0
none known

Summary

A buffer over-read vulnerability exists in bl <4.0.3, <3.0.1, <2.2.1, and <1.2.3 which could allow an attacker to supply user input (even typed) that if it ends up in consume() argument and can become negative, the BufferList state can be corrupted, tricking it into exposing uninitialized memory via regular .slice() calls.

Patch / fix

  • npm bl 1.2.3, 2.2.1, 3.0.1, 4.0.3
  • bufferlist_project bufferlist 1.2.3, 2.2.1, 3.0.1, 4.0.3
  • node-bl Debian 14, Debian 13, Debian 12 4.0.3-1

debian advisories DEBIAN-CVE-2020-8244

  • node-bl Ubuntu 18.04 LTS 1.1.2-1ubuntu1.1
  • node-bl Ubuntu Pro 16.04 LTS 0.9.3-1ubuntu0.1~esm1

ubuntu advisories UBUNTU-CVE-2020-8244

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

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-2020-8244 updated cvss 6.5

nodejs-bl: buffer over-read vulnerability leads to corrupted BufferList which can result in uninitialized memory being leaked

  • Red Hat OpenShift Container Platform 3.11 kibana Red Hat OpenShift Container Platform 4 kibana
    affected: no fix planned “Will not fix”
  • Red Hat OpenShift Container Platform 4 openshift4/ose-logging-kibana6
    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

Exploit prediction

2.10% chance of exploitation in the next 30 days, higher than 81% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • hackerone.com https://hackerone.com/reports/966347 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L
NVD 2.0 6.4 AV:N/AC:L/Au:N/C:P/I:N/A:P
GitHub 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L

Affected packages

ecosystem package affected fixed in
npm bl
<1.2.3
>=2.0.0, <2.2.1
>=3.0.0, <3.0.1
>=4.0.0, <4.0.3
1.2.3
2.2.1
3.0.1
4.0.3

Affected products

  • n/a bl

Classification

Weakness

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.