# [HIGH] Critical WebP 0-day security CVE-2023-4863 impacts wider software ecosystem

**Source:** Snyk
**Published:** 2023-09-28
**Article:** https://snyk.io/blog/critical-webp-0-day-cve-2023-4863/

## Threat Profile

Snyk Blog In this article
Written by Brian Clark 
Eric Smalling 
Jonathan Moses 
September 28, 2023
0 mins read Quick links How widely used is libwebp? 
Explaining the libwebp vulnerability 
How to detect the libwebp library with Snyk 
Prioritizing the most important libwebp fixes 
How to fix the libwebp vulnerability 
Next steps in responding to the libwebp vulnerability 
This month, Apple Security Engineering and Architecture (SEA) and The Citizen Lab at The University of Toronto's Munk School…

## Indicators of Compromise (high-fidelity only)

- **CVE:** `CVE-2023-4863`
- **CVE:** `CVE-2023-5129`
- **CVE:** `CVE-2023-41064`
- **CVE:** `CVE-2023-41061`

## MITRE ATT&CK Techniques

- **T1190** — Exploit Public-Facing Application
- **T1195.002** — Compromise Software Supply Chain
- **T1203** — Exploitation for Client Execution
- **T1189** — Drive-by Compromise

## Kill chain phases observed

_(none detected from narrative keywords)_

## Recommended hunts

### Hosts exposed to libwebp heap overflow CVE-2023-4863 / CVE-2023-5129 (TVM)

`UC_1370_2` · phase: **weapon** · confidence: **High** · AI-generated for this article

**Splunk SPL (CIM):**
```spl
| tstats summariesonly=t count min(_time) as firstSeen max(_time) as lastSeen from datamodel=Vulnerabilities where Vulnerabilities.cve IN ("CVE-2023-4863","CVE-2023-5129","CVE-2023-41064","CVE-2023-41061") by Vulnerabilities.dest Vulnerabilities.cve Vulnerabilities.severity Vulnerabilities.signature
| `drop_dm_object_name("Vulnerabilities")`
| convert ctime(firstSeen) ctime(lastSeen)
| sort - severity dest
```

**Defender KQL:**
```kql
DeviceTvmSoftwareVulnerabilities
| where CveId in ("CVE-2023-4863","CVE-2023-5129","CVE-2023-41064","CVE-2023-41061")
| join kind=leftouter (DeviceInfo | summarize arg_max(Timestamp, OSPlatform, OSVersion, PublicIP, IsInternetFacing, LoggedOnUsers) by DeviceId) on DeviceId
| project DeviceName, OSPlatform, OSVersion, SoftwareVendor, SoftwareName, SoftwareVersion, CveId, VulnerabilitySeverityLevel, RecommendedSecurityUpdate, IsInternetFacing, LoggedOnUsers
| order by IsInternetFacing desc, VulnerabilitySeverityLevel asc, DeviceName asc
```

### Unpatched libwebp-bundling apps in software inventory (Chrome, Electron, 1Password, ImageMagick, GIMP, ffmpeg)

`UC_1370_3` · phase: **weapon** · confidence: **Medium** · AI-generated for this article

**Splunk SPL (CIM):**
```spl
| tstats summariesonly=t latest(_time) as lastSeen values(Vulnerabilities.signature) as findings from datamodel=Vulnerabilities where (Vulnerabilities.signature="*libwebp*" OR Vulnerabilities.signature="*Chrome*" OR Vulnerabilities.signature="*Electron*" OR Vulnerabilities.signature="*1Password*" OR Vulnerabilities.signature="*ImageMagick*" OR Vulnerabilities.signature="*GIMP*" OR Vulnerabilities.signature="*ffmpeg*" OR Vulnerabilities.signature="*Pillow*" OR Vulnerabilities.signature="*GoDot*") AND Vulnerabilities.cve IN ("CVE-2023-4863","CVE-2023-5129") by Vulnerabilities.dest Vulnerabilities.cve Vulnerabilities.severity
| `drop_dm_object_name("Vulnerabilities")`
| convert ctime(lastSeen)
| sort - severity dest
```

**Defender KQL:**
```kql
let VulnerableConsumers = dynamic(["libwebp","webpd","google chrome","microsoft edge","electron","1password","imagemagick","gimp","ffmpeg","pillow","godot","slack","discord","signal","visual studio code","figma","notion"]);
DeviceTvmSoftwareInventory
| where SoftwareName has_any (VulnerableConsumers)
| extend NameLc = tolower(SoftwareName)
| extend LikelyUnpatched = case(
    NameLc has "libwebp" and SoftwareVersion !startswith "1.3.2" and SoftwareVersion !startswith "1.3.3" and SoftwareVersion !startswith "1.4", true,
    NameLc has "chrome" and SoftwareVersion matches regex @"^(?:[0-9]|[0-9][0-9]|1[0-1][0-9]|115|116\.0\.5845\.([01]?\d?\d|18[0-6]))\b", true,
    NameLc has "edge" and SoftwareVersion matches regex @"^(?:[0-9]|[0-9][0-9]|11[0-5])\.", true,
    NameLc has "1password" and SoftwareVersion matches regex @"^[0-7]\.|^8\.([0-9]|10\.([0-9]|1[0-4]))\b", true,
    NameLc has "electron" and SoftwareVersion matches regex @"^(?:[0-9]|1[0-9]|2[01]|22\.[0-2]|22\.3\.([0-9]|1[0-9]|2[0-3])|24\.[0-7]|24\.8\.[0-2]|25\.[0-7]|25\.8\.0|26\.[01]|26\.2\.0)\b", true,
    false)
| where LikelyUnpatched == true
| join kind=leftouter (DeviceInfo | summarize arg_max(Timestamp, OSPlatform, IsInternetFacing, LoggedOnUsers) by DeviceId) on DeviceId
| project DeviceName, OSPlatform, SoftwareVendor, SoftwareName, SoftwareVersion, IsInternetFacing, LoggedOnUsers
| order by IsInternetFacing desc, SoftwareName asc
```

### Trusted vendor binary / installer launching unusual children

`UC_SUPPLY_CHAIN` · phase: **exploit** · confidence: **Medium**

**Splunk SPL (CIM):**
```spl
| tstats `summariesonly` count min(_time) as firstTime max(_time) as lastTime
    from datamodel=Endpoint.Processes
    where Processes.parent_process_name IN ("setup.exe","installer.exe","update.exe")
      AND Processes.process_name IN ("powershell.exe","cmd.exe","rundll32.exe","regsvr32.exe","mshta.exe","wscript.exe","cscript.exe","wmic.exe","bitsadmin.exe")
    by Processes.dest, Processes.user, Processes.parent_process_name, Processes.process_name, Processes.process
| `drop_dm_object_name(Processes)`
```

**Defender KQL:**
```kql
DeviceProcessEvents
| where Timestamp > ago(7d)
| where AccountName !endswith "$"
| where InitiatingProcessFileName in~ ("setup.exe","installer.exe","update.exe")
| where FileName in~ ("powershell.exe","cmd.exe","rundll32.exe","regsvr32.exe","mshta.exe","wscript.exe","cscript.exe","wmic.exe","bitsadmin.exe")
| project Timestamp, DeviceName, AccountName, InitiatingProcessFileName, FileName, ProcessCommandLine
```

### IOC-driven hunts (use shared templates)

These are standard IOC-substitution hunts — the canonical SPL and KQL live once in [`_TEMPLATES.md`](../_TEMPLATES.md), so we don't repeat the same boilerplate on every CVE / hash / network-IOC briefing.

- **Asset exposure — vulnerability matches article CVE(s)** ([template](../_TEMPLATES.md#asset-exposure)) — phase: **recon**, confidence: **High**
  - CVE(s): `CVE-2023-4863`, `CVE-2023-5129`, `CVE-2023-41064`, `CVE-2023-41061`


## Why this matters

Severity classified as **HIGH** based on: CVE present, 4 use case(s) fired, 4 technique(s) inferred. Read the full article for actor attribution, tooling details, and any defanged IOCs in the body that aren't visible in the RSS summary.