Synacor Zimbra Collaboration Suite (ZCS) Cross-Site Scripting (XSS) Vulnerability
Synacor · Zimbra Collaboration Suite (ZCS)
A cross-site scripting flaw in the /h/autoSaveDraft function of Synacor's Zimbra Collaboration Suite (ZCS) allows script injection into its web interface. An attacker who is a remote, authenticated user can exploit it by supplying a crafted script and getting a victim to interact with the affected page.
Cross Site Scripting vulnerability in Zimbra ZCS v.8.8.15 allows a remote authenticated attacker to execute arbitrary code via a crafted script to the /h/autoSaveDraft function.
- Exploited
- Yes, in CISA KEV
- Reports
- 0
- Tactics
- 4/15
How an attack unfolds
Based on MITRE ATT&CKA public catalogue of the techniques attackers use, maintained by MITRE. Patchfirst uses it to describe what attackers do with a vulnerability. mappings. Select a step to see the evidence.Exploitation timelineDated milestones for a CVE: when it was disclosed, when exploit code became public, when exploitation was confirmed, and when threat reports named it.
First seen exploited 20 months after disclosure.
- Disclosedday 0
CISA KEV listing is when exploitation was confirmed, not necessarily the first attack.
MITRE ATT&CKA public catalogue of the techniques attackers use, maintained by MITRE. Patchfirst uses it to describe what attackers do with a vulnerability. techniques
3 TechniqueOne specific attacker behaviour in MITRE ATT&CK, such as T1190 “Exploit Public-Facing Application”. IDs with a dot, like T1059.004, are sub-techniques., grouped by TacticThe attacker’s goal at a stage of an attack in MITRE ATT&CK, such as Initial Access or Persistence. Each technique belongs to one or more tactics. in kill-chain order 3ExecutionTA0002
The /h/autoSaveDraft function in Zimbra Collaboration Suite can be targeted by an authenticated attacker's malicious scripts, facilitating arbitrary code execution, as well as session cookie theft.
Privilege EscalationTA0004
CollectionTA0009
Detection
0 rules for this CVE · 134 general rules for its techniquesRules for this CVE
0Sigma ruleAn open, vendor-neutral detection rule for log data. Security teams convert Sigma rules into searches for their own SIEM. that reference CVE-2023-34192 directly.CVE-specific rules are not available in this build. Search SigmaHQ ↗
General rules for this CVE’s techniques
These detect the technique in general, not this specific vulnerability.
Process InjectionT105537 general rules
- Antivirus PrinterNightmare CVE-2021-34527 Exploit Detectioncriticalstable
- Potential Dridex Activitycriticalstable
- CobaltStrike Named Pipecriticaltest
- CobaltStrike Named Pipe Pattern Regexcriticaltest
- HackTool - DInjector PowerShell Cradle Executioncriticaltest
- Malicious Named Pipe Createdcriticaltest
- RedSun - Named Pipe Createdcriticalexperimental
- RedSun - TieringEngineService.exe Detected as EICAR Test Filecriticalexperimental
Command and Scripting InterpreterT105995 general rules
- HackTool - Sliver C2 Implant Activity Patterncriticaltest
- Lazarus Group Activitycriticaltest
- REvil Kaseya Incident Malware Patternscriticaltest
- Turla Group Lateral Movementcriticaltest
- Windows Defender AMSI Trigger Detectedhighstable
- Windows Defender Threat Detectedhighstable
- Abusable DLL Potential Sideloading From Suspicious Locationhightest
- Add Insecure Download Source To Wingethightest
Browser Session HijackingT11852 general rules
Sigma rules © SigmaHQ, Detection Rule License 1.1; linked, not reproduced.
What security researchers reported
Not named in any threat report yetAlso mentioned in 50 community threat pulses (AlienVault OTX)
Weaker evidencePulses are indicator collections that anyone can publish. A mention is not confirmation of exploitation.
- Actively_Exploited_Kev | Oct 29, 202628 Oct 2026
- Actively_Exploited_Kev | Oct 28, 202627 Oct 2026
- Actively_Exploited_Kev | Oct 27, 202626 Oct 2026
- Actively_Exploited_Kev | Oct 24, 202623 Oct 2026
- Actively_Exploited_Kev | Oct 23, 202622 Oct 2026
- Actively_Exploited_Kev | Oct 22, 202621 Oct 2026
- 44 more on OTX