Spreadsheet::ParseExcel Remote Code Execution Vulnerability
Spreadsheet::ParseExcel · Spreadsheet::ParseExcel
Spreadsheet::ParseExcel version 0.65, a Perl module for parsing Excel files, contains an arbitrary code execution flaw in which unvalidated input read from a file is passed into a string-type "eval", specifically through the evaluation of Number format strings in the Excel parsing logic. An attacker can get code to run by supplying a crafted Excel file that a user opens or processes with the module, which requires local access and user interaction.
Spreadsheet::ParseExcel version 0.65 is a Perl module used for parsing Excel files. Spreadsheet::ParseExcel is vulnerable to an arbitrary code execution (ACE) vulnerability due to passing unvalidated input from a file into a string-type “eval”. Specifically, the issue stems from the evaluation of Number format strings (not to be confused with printf-style format strings) within the Excel parsing logic.
- Exploited
- Yes, in CISA KEV
- Reports
- 0
- Tactics
- 2/15
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 1 day after disclosure. Public exploit code (Metasploit) was available the same day.
- First seen exploitedVulnCheck KEV evidence+1 day
- Added to CISA KEVEU database agrees+9 days
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
2 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 2ExecutionTA0002
This vulnerability is exploited by a remote attacker by passing unvalidated input from a file into a string-type "eval". Specifically, the issue stems from the evaluation of Number format strings (not to be confused with printf-style format strings) within the Excel parsing logic. After successful exploitation, the attacker gains the ability to perform remote code execution. This vulnerability has been targeted by Chinese hackers who exploited the vulnerability in Spreadsheet::ParseExcel to compromise appliances. In collaboration with cybersecurity firm Mandiant, Barracuda assesses that the threat actor behind the attacks is UNC4841, who leveraged the flaw to deploy ‘SeaSpy’ and ‘Saltwater’ malware.
Command and ControlTA0011
Lower-confidence links (1)
These come from early or generic mappings, text matching, or contradict this CVE’s details (for example a public-facing technique on a bug that needs a user to open a file). Shown for completeness.
- Exploit Public-Facing ApplicationT1190 needs user interaction; not a public-facing exploit
Detection
0 rules for this CVE · 182 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-2023-7101 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.
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
Ingress Tool TransferT110587 general rules
- Greenbug Espionage Group Indicatorscriticaltest
- Pandemic Registry Keycriticaltest
- Curl Download And Execute Combinationhightest
- File Download And Execution Via IEExec.EXEhightest
- File Download From IP Based URL Via CertOC.EXEhightest
- File Download Using Notepad++ GUP Utilityhightest
- File Download Via Bitsadmin To A Suspicious Target Folderhightest
- File Download Via Windows Defender MpCmpRun.EXEhightest
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 30, 202629 Oct 2026
- 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
- 44 more on OTX