Threats / Synacor / CVE-2024-45519
CVE-2024-45519
· EUVD no mirror located
· GCVE no mirror located
Verified 2026-08-04
Synacor Zimbra Collaboration Suite (ZCS) vulnerability
Synacor Zimbra Collaboration Suite contains an unspecified vulnerability in the postjournal service allowing unauthenticated command execution.
Verdict
Today item — known-exploited.
An unauthenticated attacker can execute arbitrary commands on affected Zimbra Collaboration Suite instances via the postjournal service. The vulnerability is actively exploited in the wild with high exploit probability.
CISA KEV Yes · 2024-10-035EPSS 0.99877 (verify live)6Exploit Weaponized · public PoC7CVSS 103CISA SSVC Exploitation: active · Automatable: yes · Impact: total4
01
Is it exploitable?
— the evidence, ranked above the scoreExploit available
Fully weaponized — public exploit code is cataloged for this vulnerability.We link the existence of the exploit; we do not host or redistribute payloads.
Reported exploitation
6 independent public reports of in-the-wild exploitation are cataloged.Distinct reporting sources (vendor, incident response, government); open them for the underlying claims.
Exploited in the wild
Listed in the CISA Known Exploited Vulnerabilities catalog (added 2024-10-03).
Probability (EPSS)
EPSS 0.99877 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
CVSS 10 (CVSS:3.1/AC:L/AV:N/A:H/C:H/I:H/PR:N/S:C/UI:N) · Affected: Synacor, Zimbra Collaboration Suite (ZCS). Confirm exact fixed builds in the vendor advisory.CVSS — CNA-assigned (CVE.org), version 3.1, set at disclosure.
Weakness (CWE)
Mapped to CWE-284 Improper Access Control — weakness family: Authorization / access control.CWE assignment from the public NVD record (may be stale); the weakness class drives how the flaw is exploited.
CISA SSVC (triage disposition)
Exploitation: active · Automatable: yes · Technical Impact: totalCISA's own stakeholder-specific triage inputs, published in the CVE record (CISA Coordinator role). NOTE: this is CISA's three decision points; the final Act/Attend/Track decision also requires a Mission & Well-being input not published here, so no overall decision is asserted.
Currency of the record
CISA added this to its KEV catalog 1 day after the CVE record was published.KEV lag = CISA-KEV dateAdded − CVE.org datePublished; a floor on how long the known-exploited flaw sat in the public record before the federal catalog listed it. Severity/weakness here is CNA- or CISA-assigned (current at disclosure), independent of NVD's analysis backlog.
Public exploit available
Public exploit tooling is catalogued for this CVE (a public proof-of-concept / detection template). Catalog entries: nuclei template. We link the catalog page(s) only — no payload or code is hosted or restated here.Link, never host — the catalog page is the source; basicsecurity.net does not redistribute payloads.
02
Who’s exploiting it?
— attribution turns risk into urgencyAttribution not established
No confirmed (advisory-backed) threat-actor attribution is established for this record. Absence of a named actor is not absence of compromise — see Coverage & confidence.
03
Why it matters
— the attack path, told twice: adversary, then board1
Front door — unauthenticated access narrative 1
Attacker
I identify the postjournal service as exposed and accessible without authentication.
Business
The organization has deployed Zimbra without proper network segmentation or access controls on internal services.
2
Keys to the kingdom — privilege/identity takeover narrative 2
Attacker
I craft a request to the postjournal service that triggers command execution through the unspecified vulnerability.
Business
The service fails to validate or sanitize input, allowing injection of arbitrary commands.
3
Lateral reach — past segmentation narrative 3
Attacker
I execute commands with the privileges of the Zimbra service process to establish persistence or pivot deeper into the infrastructure.
Business
The organization loses control of the mail server and faces potential data exfiltration, service disruption, and lateral movement into connected systems.
04
What to do
— defensible action- Remediate per the vendor advisory — confirm the fixed build for your version and verify exposure.1
Say it to the boardA vulnerability with this evidence profile is a defensible budget line, not a backlog ticket — fund the change against the proof above.
05