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CVE-2019-1748· NVD / CVE Program· CNA cisco

Cisco IOS and IOS XE Software Network Plug-and-Play Agent Certificate Validation Vulnerability

A vulnerability in the Cisco Network Plug-and-Play (PnP) agent of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to gain unauthorized access to sensitive data. The vulnerability exists because the affected software insufficiently validates certificates. An attacker could exploit this vulnerability by supplying a crafted certificate to an affected device. A successful exploit could allow the attacker to conduct man-in-the-middle attacks to decrypt and modify confidential information on user connections to the affected software.

HighCVSS 7.4 · v3.1—No exploit No fix recorded
Published
Mar 27, 2019
Updated
Jun 16, 2026
EPSS
1.2% · 67th percentile
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Report tools

JSON

Action score

29

Monitor

Low priority for now.

CVSS
29 / 40 · 7.4 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 1.2%

CNA vs NVD score

NVD
7.4
CNA · cisco
7.4
agree

CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Affected systems

VendorProduct
ciscoios
ciscoios xe

Affected versions

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

  • cisco ios12.0(1)
  • cisco ios12.0(1)t
  • cisco ios12.0(1)t1
  • cisco ios12.0(1)xe
  • cisco ios12.0(10)
  • cisco ios12.0(10)s
  • cisco ios12.0(10)s1
  • cisco ios12.0(10)s2
  • cisco ios12.0(10)s3
  • cisco ios12.0(10)s3b
  • cisco ios12.0(10)s4
  • cisco ios12.0(10)s5
  • cisco ios12.0(10)s6
  • cisco ios12.0(10)s7
  • cisco ios12.0(10)s8
  • cisco ios12.0(10)st
  • cisco ios12.0(10)st1
  • cisco ios12.0(10)st2
  • cisco ios12.0(10a)
  • cisco ios12.0(11)

Versions reported by the vendor

Affected version ranges reported by the assigning authority (cisco). Independent of NVD's CPE analysis and usually ahead of it.

  • Cisco Cisco IOS and IOS XE Software

    • 3.7.7S, 3.9.1S, 3.9.0S, 3.9.2S, 3.9.1aS, 3.9.0aS, 3.3.0SE, 3.3.1SE, 3.3.2SE, 3.3.3SE, 3.3.4SE, 3.3.5SE … (+28)affected

Same product

cisco: all records

Other highest-scoring records for the same primary product.

  • CVE-2018-0171A vulnerability in the Smart Install feature of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attackerKEV
    99Now
  • CVE-2017-3881A vulnerability in the Cisco Cluster Management Protocol (CMP) processing code in Cisco IOS and Cisco IOS XE Software could allow an unautheKEV
    99Now
  • CVE-2017-6736The Simple Network Management Protocol (SNMP) subsystem of Cisco IOS and IOS XE Software contains multiple vulnerabilities that could allow KEV
    86Now
  • CVE-2016-6415The server IKEv1 implementation in Cisco IOS 12.2 through 12.4 and 15.0 through 15.6, IOS XE through 3.18S, IOS XR 4.3.x and 5.0.x through 5KEV
    86Now
  • CVE-2017-6737A vulnerability in the SNMP implementation of could allow an authenticated, remote attacker to cause a reload of the affected system or to rKEV
    79This week
  • CVE-2017-12240The DHCP relay subsystem of Cisco IOS 12.2 through 15.6 and Cisco IOS XE Software contains a vulnerability that could allow an unauthenticatKEV
    73This week

Remediation

Which version to upgrade to

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

No fix version is recorded for this entry. Check the references for vendor advisories.

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.

Credits

All researchers

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

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

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.
  • Special conditions such as timing or configuration are required.

If successful

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

Weakness class (CWE)

CWE-295 · Improper Certificate Validation

CVSS vector

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

nvd-primary

Root cause

A certificate validation error is silently swallowed instead of terminating the connection. Often, code added for a test environment makes its way into production.

The bug in code

The whole CWE-295 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

kotlin
override fun checkServerTrusted(chain: Array<X509Certificate>, type: String) {  // Left empty for the test environment}

Fixed

kotlin
val client = OkHttpClient.Builder()  .certificatePinner(    CertificatePinner.Builder()      .add("api.sirius.example", "sha256/…")      .build()  ).build()

Attack context

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

ATT&CK techniques

—

Change log

No changes recorded on tracked fields yet. Score, KEV, exploit maturity and fix status changes appear here.

References

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records