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CVE-2016-6303· NVD / CVE Program· CNA redhat

Integer overflow in the MDC2_Update function in crypto/mdc2/mdc2dgst.c in OpenSSL before 1.1.0 allows remote attackers to cause a denial of

Integer overflow in the MDC2_Update function in crypto/mdc2/mdc2dgst.c in OpenSSL before 1.1.0 allows remote attackers to cause a denial of service (out-of-bounds write and application crash) or possibly have unspecified other impact via unknown vectors.

CriticalCVSS 9.8 · v3.1—No exploit Fix available
Published
Sep 16, 2016
Updated
Jun 16, 2026
EPSS
32.0% · 98th percentile
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Report tools

JSON

Action score

49

Plan

Add it to your regular patch cycle.

CVSS
39 / 40 · 9.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
10 / 30 · 32.0%

Affected systems

VendorProduct
opensslopenssl
nodejsnode.js

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • nodejs node.jsbefore 0.12.16
  • nodejs node.js4.0.0 and later · before 4.6.0
  • nodejs node.js6.0.0 and later · before 6.6.0

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Alpine:v3.2opensslbefore 1.0.2h-r31.0.2h-r3
Debian:12opensslbefore 1.0.2i-11.0.2i-1
Debian:7opensslbefore 1.0.1t-1+deb7u11.0.1t-1+deb7u1
Debian:8opensslbefore 1.0.1t-1+deb8u41.0.1t-1+deb8u4
SUSE:Linux Enterprise Desktop 12 SP1compat-openssl098before 0.9.8j-102.10.9.8j-102.1
SUSE:Linux Enterprise Desktop 12 SP1opensslbefore 1.0.1i-52.11.0.1i-52.1
SUSE:Linux Enterprise Server 11-SECURITYopenssl1before 1.0.1g-0.52.11.0.1g-0.52.1
SUSE:Linux Enterprise Server for SAP Applications 11 SP3compat-openssl097gbefore 0.9.7g-146.22.47.10.9.7g-146.22.47.1
SUSE:Linux Enterprise Server for SAP Applications 12opensslbefore 1.0.1i-27.21.11.0.1i-27.21.1
SUSE:Linux Enterprise Software Development Kit 11 SP4opensslbefore 0.9.8j-0.102.20.9.8j-0.102.2

Other highest-scoring records for the same primary product.

  • CVE-2014-0160The (1) TLS and (2) DTLS implementations in OpenSSL 1.0.1 before 1.0.1g do not properly handle Heartbeat Extension packets, which allows remKEV
    90Now
  • CVE-2021-3711SM2 Decryption Buffer Overflow
    65This week
  • CVE-2003-0545Double free vulnerability in OpenSSL 0.9.7 allows remote attackers to cause a denial of service (crash) and possibly execute arbitrary code
    65This week
  • CVE-2016-2108The ASN.1 implementation in OpenSSL before 1.0.1o and 1.0.2 before 1.0.2c allows remote attackers to execute arbitrary code or cause a denia
    62This week
  • CVE-2016-6309statem/statem.c in OpenSSL 1.1.0a does not consider memory-block movement after a realloc call, which allows remote attackers to cause a den
    60This week
  • CVE-2022-3786X.509 Email Address Variable Length Buffer Overflow
    58Plan

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
alpine:openssl1.0.2h-r3 · Alpine:v3.2Package registry (OSV)
debian:openssl1.0.2i-1 · Debian:12Package registry (OSV)
suse:compat-openssl097g0.9.7g-146.22.47.1 · SUSE:Linux Enterprise Server for SAP Applications 11 SP3Package registry (OSV)
suse:compat-openssl0980.9.8j-102.1 · SUSE:Linux Enterprise Desktop 12 SP1Package registry (OSV)
suse:openssl1.0.1i-27.21.1 · SUSE:Linux Enterprise Server for SAP Applications 12Package registry (OSV)
suse:openssl11.0.1g-0.52.1 · SUSE:Linux Enterprise Server 11-SECURITYPackage registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

The product’s vendor appears in a public program. Matched by name; verify the scope text in the program.

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
high · data can be read
Integrity
high · data or configuration can be modified
Availability
high · the service can be disrupted
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

CWE-787 · Out-of-bounds Write

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Noroxi analysis

No Noroxi analysis for this record yet

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Change log

  1. Fix✗ → ✓

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References

All records