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Fencer Vulns
high 7.5

CVE-2016-6305 in the critical feed json

The ssl3_read_bytes function in record/rec_layer_s3.c in OpenSSL 1.1.0 before 1.1.0a allows remote attackers to cause a denial of service (…

published 2016-09-26 10 y ago modified 2026-06-17 4 mo ago also EUVD-2016-7234

cvss
7.5
version 3.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
16.0%
EPSS 16.0% chance of exploitation in 30 days, percentile 96%
public exploits
0
none known

Summary

The ssl3_read_bytes function in record/rec_layer_s3.c in OpenSSL 1.1.0 before 1.1.0a allows remote attackers to cause a denial of service (infinite loop) by triggering a zero-length record in an SSL_peek call.

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-2016-6305 updated cvss 5.9

openssl: SSL_peek() hang on empty record

  • Red Hat Enterprise Linux 4 openssl Red Hat Enterprise Linux 5 openssl, openssl097a Red Hat Enterprise Linux 6 openssl, openssl098e, openssl-perl Red Hat Enterprise Linux 7 openssl, openssl098e, openssl-libs, openssl-perl Red Hat JBoss Enterprise Application Platform 5 openssl Red Hat JBoss Enterprise Application Platform 6 openssl
    +3 more products
    Red Hat JBoss Enterprise Web Server 1 openssl Red Hat JBoss Enterprise Web Server 2 openssl Red Hat JBoss Enterprise Web Server 3 openssl
    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

cisa ICSA-22-349-21 updated cvss 7.5

Siemens SCALANCE X-200RNA Switch Devices

  • Siemens SCALANCE X204RNA (HSR) (6GK5204-0BA00-2MB2) <V3.2.7 Siemens SCALANCE X204RNA (PRP) (6GK5204-0BA00-2KB2) <V3.2.7 Siemens SCALANCE X204RNA EEC (HSR) (6GK5204-0BS00-2NA3) <V3.2.7 Siemens SCALANCE X204RNA EEC (PRP) (6GK5204-0BS00-3LA3) <V3.2.7 Siemens SCALANCE X204RNA EEC (PRP/HSR) (6GK5204-0BS00-3PA3) <V3.2.7
    affected: fixed in V3.2.7, mitigation support.industry.siemens.com

Facts from CISA's republication of the vendor's own advisory (CSAF); the linked advisory is the authoritative source. CISA notification · csaf

Exploit prediction

16.00% chance of exploitation in the next 30 days, higher than 96% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/openssl/openssl/issues/1563 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.0 7.5 CVSS:3.0/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

Classification

Weakness
  • CWE-20 Improper Input Validation
Technology feeds

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.