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NVD / CVE Program· CNA cisco

CVE-2021-1516: Cisco Content Security Management Appliance, Email Security Appliance, and Web Security Appliance Information Disclosure Vulnerability

Noroxi assessment

Priority: Monitor (action score 26/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 1% (FIRST EPSS); higher than 63.1% of all records.
  • Anyone who can reach it over the internet can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
  • According to the record, no fixed version is available yet.
  • Severity is disputed: the assigning authority (CNA) scores it 4.3, NVD 6.5.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Update when a fix is released; follow the vendor's advisory.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

A vulnerability in the web-based management interface of Cisco AsyncOS Software for Cisco Content Security Management Appliance (SMA), Cisco Email Security Appliance (ESA), and Cisco Web Security Appliance (WSA) could allow an authenticated, remote attacker to access sensitive information on an affected device. The vulnerability exists because confidential information is included in HTTP requests that are exchanged between the user and the device. An attacker could exploit this vulnerability by looking at the raw HTTP requests that are sent to the interface. A successful exploit could allow the attacker to obtain some of the passwords that are configured throughout the interface.

MediumCVSS 6.5 · v3.1—No exploit No fix recorded
Published
May 6, 2021
Updated
Jun 16, 2026
EPSS
1.0% · 63th percentile

Report tools

JSON

Action score

26

Monitor

Low priority for now.

CVSS
26 / 40 · 6.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 1.0%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
6.5
CNA · cisco
4.3
2.2 point gap

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

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

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • No fixed version yet

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2021-1516

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

One daily email digest (06:00 UTC); connect a webhook for KEV listings and weaponized exploits instantly.

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
ciscocontent security management appliance
ciscoemail security appliance
ciscoweb security appliance
ciscoasyncos
ciscoironport web security appliance

Affected versions

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

  • cisco content security management applianceall versions
  • cisco email security applianceall versions
  • cisco ironport web security appliance13.6.2-023
  • cisco ironport web security appliance14.0.0-090
  • cisco ironport web security appliance14.0.0-133
  • cisco ironport web security appliance14.0.0-292
  • cisco ironport web security appliance14.0.0-300
  • cisco web security applianceall versions

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 Web Security Appliance (WSA)

    • n/aaffected

Same product

cisco: all records

Other highest-scoring records for the same primary product.

  • CVE-2013-3395Cross-site request forgery (CSRF) vulnerability in the web framework on Cisco IronPort Web Security Appliance (WSA) devices, Email Security
    27Monitor
  • CVE-2021-1447Cisco Content Security Management Appliance Privilege Escalation Vulnerability
    26Monitor
  • CVE-2020-3447Cisco Email Security Appliance and Cisco Content Security Management Appliance Information Disclosure Vulnerability
    26Monitor

Published before and after this one in the same product

  • ← EarlierCVE-2019-1983Sep 22, 2020 · Cisco Email Security Appliance and Cisco Content Security Management Appliance Denial of Service Vulnerability
    22Monitor
  • ← EarlierCVE-2020-3117Sep 22, 2020 · Cisco Web Security Appliance and Cisco Content Security Management Appliance HTTP Header Injection Vulnerability
    18Monitor
  • ← EarlierCVE-2021-1129Jan 20, 2021 · Cisco Email Security Appliance, Cisco Content Security Management Appliance, and Cisco Web Security Appliance Information Disclosure Vulnerability
    21Monitor

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.

No history yet (it accumulates with the daily EPSS job).

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).

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

All national notices →

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • A low-privileged account is enough.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

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

Weakness class (CWE)

CWE-540 · Inclusion of Sensitive Information in Source Code

CVSS vector

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

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.

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