Threats / Synacor / CVE-2022-27924
CVE-2022-27924
· EUVD no mirror located
· GCVE no mirror located
Verified 2026-06-22
Synacor Zimbra Collaboration Suite (ZCS) vulnerability
Synacor Zimbra Collaboration Suite allows attackers to inject memcache commands, overwriting arbitrary cached entries and enabling authentication bypass or data manipulation.
Verdict
Today item, not a backlog item.
A memcache injection vulnerability in ZCS permits unauthenticated command injection leading to cache poisoning. Active exploitation in ransomware campaigns and high EPSS score indicate immediate threat to deployed instances.
01
Is it exploitable?
— the evidence, ranked above the scoreReported exploitation
10 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 2022-08-04), flagged for known ransomware use.
Probability (EPSS)
EPSS 0.84593 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
Affected: Synacor, Zimbra Collaboration Suite (ZCS). Confirm exact fixed builds in the vendor advisory.
Weakness (CWE)
Mapped to CWE-93 CWE-93 — weakness family: Injection.CWE assignment from the public NVD record; the weakness class drives how the flaw is exploited.
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 craft malicious memcache protocol commands targeting the ZCS instance's cache layer.
Business
Attackers gain ability to manipulate cached authentication tokens and session data without credentials.
2
Keys to the kingdom — privilege/identity takeover narrative 2
Attacker
I inject commands that overwrite cached entries controlling user sessions or administrative privileges.
Business
Legitimate users are locked out or attacker accounts gain elevated access to email and collaboration systems.
3
Lateral reach — past segmentation narrative 3
Attacker
I leverage cache poisoning to bypass security controls and establish persistent access.
Business
Ransomware operators deploy encryption payloads across the organization's messaging infrastructure and data stores.
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