CVE-2022-20960

highpriority · track · 30EPSS 0.008 · 58 %ileEURUUS

grimoire priorityP2 · Scheduled

Exploitable?

—

no known exploitation

Likely / severe?

0.85% (58th) EPSS

CVSS 7.5 · high

Is it mine?

22 products

Check your exposure

Who says so?

4 sources

cnnvd · enisa_euvd · fstec_bdu · cisco_csaf

EPSS · scored 2026-10-27

A vulnerability in Cisco AsyncOS Software for Cisco Email Security Appliance (ESA) could allow an unauthenticated remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to improper handling of certain TLS connections that are processed by an affected device. An attacker could exploit this vulnerability by establishing a large number of concurrent TLS connections to an affected device. A successful exploit could allow the attacker to cause the device to drop new TLS email messages that come from the associated email servers. Exploitation of this vulnerability does not cause the affected device to unexpectedly reload. The device will recover autonomously within a few hours of when the attack is halted or mitigated.

remediations

Vendor fix, mitigation, or workaround guidance, as published by each source.

A vendor fix is available.

FixedCisco Secure Emailcisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com

cvss

Technical severity, 0–10. One row per scoring source.

7.5

010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 6.9–7.5

v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Hprimary · NVD / NIST USexploitability 3.9 · impact 3.6

v3.17.5highAV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Hsecondary · FSTEC (BDU) RU

v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Hsecondary · ENISA EU

v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Hsecondary · psirt@cisco.com USexploitability 3.9 · impact 3.6

v3.16.9mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:Usecondary · CVSS-BT (t0sche)

v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Hsecondary · Cisco PSIRT US

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-295USprimaryCWE-295USCWE-400USCWE-400US

affected products (22)

Products and version ranges known to be affected.

Cisco Cisco Secure Emailall versionscisco_csafUS
Cisco Cisco Secure Email≤ 11.1.0-131enisa_euvdEU
Cisco Cisco Secure Email≤ 11.1.0-128enisa_euvdEU
Cisco Cisco Secure Email≤ 12.1.0-071enisa_euvdEU
Cisco Cisco Secure Email≤ 12.0.0-419enisa_euvdEU
Cisco Cisco Secure Email≤ 13.0.0-392enisa_euvdEU
Cisco Cisco Secure Email≤ 12.5.0-066enisa_euvdEU
Cisco Cisco Secure Email≤ 12.1.0-087enisa_euvdEU
Cisco Cisco Secure Email≤ 11.0.3-238enisa_euvdEU
Cisco Cisco Secure Email≤ 14.0.0-698enisa_euvdEU
Cisco Cisco Secure Email≤ 14.2.0-620enisa_euvdEU
Cisco Cisco Secure Email≤ 12.1.0-089enisa_euvdEU
Cisco Cisco Secure Email≤ 13.5.1-277enisa_euvdEU
Cisco Cisco Secure Email≤ 11.1.0-069enisa_euvdEU
Cisco Systems Inc. AsyncOS≤ 14.0fstec_bduRU
Cisco Systems Inc. AsyncOS≤ 13.5fstec_bduRU
Cisco Systems Inc. AsyncOS≤ 13.0fstec_bduRU
Cisco Systems Inc. AsyncOS≤ 12.5.0fstec_bduRU
Cisco Systems Inc. AsyncOS14.2 → 14.2.1-015fstec_bduRU
Cisco Systems Inc. AsyncOS14.3 → 14.3.0-020fstec_bduRU

showing 20 of 22

advisories (1)

Vendor and ecosystem advisories describing this.

cisco-sa-esa-dos-gdghHmbVCisco Email Security Appliance Denial of Service Vulnerability2022-11-02csaf · cisco_csafUS
A vulnerability in Cisco AsyncOS Software for Cisco Email Security Appliance (ESA) could allow an unauthenticated remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to improper handling of certain TLS connections that are processed by an affected device. An attacker could exploit this vulnerability by establishing a large number of concurrent TLS connections to an affected device. A successful exploit could allow the attacker to cause the device to drop new TLS email messages that come from the associated email servers. Exploitation of this vulnerability does not cause the affected device to unexpectedly reload. The device will recover autonomously within a few hours of when the attack is halted or mitigated. Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability.

also known as (4)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd fstec_bdu cisco_csaf NVD CVE.org MITRE

published 2022-11-04modified 2026-06-17

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references (6)

External citations — patches, advisories, analysis.

scry

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