CVE-2020-7796: Synacor exploited

Advisory generated from the CVE record, CISA, Exploit Observer and VEDAS: what it is, whether it is exploited, who is affected, and how to fix and detect it.

What it is

Zimbra Collaboration Suite (ZCS) before 8.8.15 Patch 7 allows SSRF when WebEx zimlet is installed and zimlet JSP is enabled.

Description quoted from the CVE record (assigned by mitre, published 2020-02-18).

Weakness: CWE-918 Server-Side Request Forgery (SSRF)

How it can be exploited

Exploitable over the network with low attack complexity needing no privileges and no user interaction. Impact: confidentiality high, integrity high, availability high. CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CISA assessment (SSVC): CISA assesses exploitation as active. Automatable: yes. Technical impact: total.

On CISA KEV since: 2026-02-17
US federal deadline: 2026-03-10
Ransomware use: Not known

Public exploit evidence (Exploit Observer)

Also known as: BDU:2026-02233, CNNVD-202002-933, CNVD-2020-12680, EUVD-2020-28728, GHSA-qfxw-56c6-7pjg

VEDAS cluster: VEDAS:BERRYFALL

Exploit Observer links 6 pieces of public exploit code or detection modules that name this CVE or one of its aliases.

Exploit code and modules (6)

Code that names this CVE. A repository can be a working exploit, a scanner, a fake or malware; read it before running anything.

Vulnerability databases and vendor advisories (7)

Catalogue entries, not exploit evidence.

Vulnerability database or vendor advisory: https://euvd.enisa.europa.eu/enisa/EUVD-2020-28728
Vulnerability database or vendor advisory: https://github.com/advisories/GHSA-qfxw-56c6-7pjg
Vulnerability database or vendor advisory: https://nvd.nist.gov/vuln/detail/CVE-2020-7796
Vulnerability database or vendor advisory: https://osv.dev/vulnerability/CVE-2020-7796
Vulnerability database or vendor advisory: https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2020-7796
Vulnerability database or vendor advisory: https://www.cnnvd.org.cn/home/globalSearch?keyword=CNNVD-202002-933
Vulnerability database or vendor advisory: https://www.cnvd.org.cn/flaw/show/CNVD-2020-12680

47 more references returned by Exploit Observer did not name this CVE or an alias, so they are left out.

VEDAS data as of 2026-11-01T17:12 UTC; fetched 2026-11-02.

Live scores

EPSS: 0.936
very likely to be attacked soon
VEDAS: 0.984
strong exploit evidence
On CISA KEV: Yes, since 2026-02-17
Detection rule: Nuclei · Suricata

EPSS (chance of attack)

VEDAS (exploit evidence)

Thin horizontal line: the “likely” (EPSS 0.10) or “strong” (VEDAS 0.90) threshold. Shaded “no data” areas are periods when cve-scores did not publish. The vertical line is the day CISA added it to its exploited list.

VEDAS flagged this bug about 184 days before CISA confirmed attacks.

Who is affected

Product	Affected	Not affected
Not stated	version n/a	Not stated

Version ranges exactly as the CVE record states them. “Before X” means X is the first fixed version.

How to fix it

CISA required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

Vendor guidance:

How to detect it

Nuclei template (active check)

Zimbra Collaboration - Server-Side Request Forgery
Zimbra Collaboration Suite (ZCS) before 8.8.15 Patch 7 allows SSRF when WebEx zimlet is installed and zimlet JSP is enabled.

Name and description quoted from the template, written by VEDAS.

The template sends 1 request (GET /zimlet/com_zimbra_webex/httpPost.jsp?companyId=http://{{interactsh...); it confirms through an out-of-band callback (interactsh), so the scanner must be able to receive it; it decides using word matchers. Severity in the template: critical. Marked as not yet verified against a live vulnerable target.

Run it against a host you own or are authorised to test:

bash

nuclei -u https://your-host -t CVE-2020-7796.yaml

Show the template (31 lines)

yaml

id: CVE-2020-7796

info:
  name: "Zimbra Collaboration - Server-Side Request Forgery"
  author: vedas-arpsyndicate
  severity: critical
  description: |
    Zimbra Collaboration Suite (ZCS) before 8.8.15 Patch 7 allows SSRF when WebEx zimlet is installed and zimlet
    JSP is enabled.
  reference:
    - https://www.exploit.observer/?keyword=CVE-2020-7796&match=exact
    - https://subdomain.center/?engine=ammonites&keyword=zimbra&match=exact
  classification:
    cvss-metrics: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
    cvss-score: 9.8
    cve-id: CVE-2020-7796
    cwe-id: CWE-918
  metadata:
    verified: false
  tags: cve,cve2020,zimbra,ssrf,oast,synacor,vkev,vuln,kev
http:
  - raw:
      - |
        GET /zimlet/com_zimbra_webex/httpPost.jsp?companyId=http://{{interactsh-url}}%23 HTTP/1.1
        Host: {{Hostname}}

    matchers:
      - type: word
        part: interactsh_protocol # Confirms the HTTP Interaction
        words:
          - "http"

CVE-2020-7796.yaml on GitHub

Suricata rules (network detection)

1 rule that alert on traffic matching this exploit: VEDAS CVE-2020-7796 Zimbra Collaboration - Server-Side Request Forgery. Add them to your Suricata rule set and reload.

Show the rules

suricata

alert http $EXTERNAL_NET any -> $HTTP_SERVERS $HTTP_PORTS (msg:"VEDAS CVE-2020-7796 Zimbra Collaboration - Server-Side Request Forgery"; flow:established,to_server; http.uri; content:"com_zimbra_webex"; nocase; content:"=http://"; nocase; fast_pattern; classtype:web-application-attack; reference:cve,CVE-2020-7796; reference:url,https://www.exploit.observer/?keyword=CVE-2020-7796&match=exact; reference:url,https://subdomain.center/?engine=ammonites&keyword=zimbra&match=exact; sid:1010895; rev:1;)

CVE-2020-7796.rules on GitHub

References

Government sources

https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2020-7796 (government-resource)

Other references

https://wiki.zimbra.com/wiki/Zimbra_Releases/8.8.15/P7 (x_refsource_CONFIRM)

Other databases

Where this comes from

This advisory is generated automatically by VEDAS from: CVE.org record, CISA KEV, cve-scores (EPSS and VEDAS), Exploit Observer, vedas-signatures. Text in quotes is reproduced from the source; everything else is a fixed template filled with source fields. Nothing here is written by a language model. Check the vendor advisory before acting, and read how VEDAS and Exploit Observer work, and their limits.