Review reviewHigh

CVE-2020-22552

snap7

The Snap7 server component in version 1.4.1, when an attacker sends a crafted packet with COTP protocol the last-data-unit flag set to No and S7 writes a var function, the Snap7 server will be crashed.

CVSS
7.5
EPSS
1.47%
71.3% percentile
CISA KEV
Not listed
Published
2020.10.28
PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV
Exploit probability1.47%
Technical severityCVSS 7.5

Vulnerability overview

The Snap7 server component in version 1.4.1, when an attacker sends a crafted packet with COTP protocol the last-data-unit flag set to No and S7 writes a var function, the Snap7 server will be crashed.

Affected product and versions

Product
snap7
Affected versions
1.4.1
Fixed versions
No verified fixed-version field is available yet

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide
  1. 1
    Identify

    Confirm that snap7 and an affected version are present.

  2. 2
    Prioritize

    Combine exploitation signals with asset exposure and business criticality.

  3. 3
    Remediate

    Follow the vendor advisory or supported update path and preserve rollback options.

  4. 4
    Verify

    Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CWE
Not available