CVE-2023-40013
HIGHSVG Loader is a javascript library that fetches SVGs using XMLHttpRequests and injects the SVG code in the tag's place. According to the docs, svg-loader will strip all JS code before…
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Description
SVG Loader is a javascript library that fetches SVGs using XMLHttpRequests and injects the SVG code in the tag's place. According to the docs, svg-loader will strip all JS code before injecting the SVG file for security reasons but the input sanitization logic is not sufficient and can be trivially bypassed. This allows an attacker to craft a malicious SVG which can result in Cross-site Scripting (XSS). When trying to sanitize the svg the lib removes event attributes such as onmouseover, onclick but the list of events is not exhaustive. Any website which uses external-svg-loader and allows its users to provide svg src, upload svg files would be susceptible to stored XSS attack. This issue has been addressed in commit d3562fc08 which is included in releases from 1.6.9. Users are advised to upgrade. There are no known workarounds for this vulnerability.
Affected Products
svg loadershubhamjainDetection & mitigation playbook
Vendor / applianceDetect
Inventory every shubhamjain svg loader deployment and check each version against the affected-products list above. Because the exploit targets the running system rather than your application code, also watch for exploitation at the network and runtime layer — O3 flags the exploit behaviour from runtime telemetry and egress traffic even before a vulnerable build is confirmed.
Remediation status
No patch has shipped for CVE-2023-40013 yet — track the shubhamjain svg loader advisory for a fixed release and apply the workarounds below in the meantime.
Mitigate without a patch
Cut exposure now: restrict the management/admin interface to trusted networks, segment the device, and apply the vendor's recommended configuration mitigations and any WAF/IPS signature. O3's runtime protection blocks the exploit chain at execution, holding the line on unpatched or end-of-life systems until you can patch.
How O3 protects you
O3 detects and blocks CVE-2023-40013 exploitation at runtime: eBPF exploit-chain detection, plus L7 egress monitoring that catches the post-exploitation callback and severs the attacker's outbound channel.
Tailored to CVE-2023-40013. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2023-40013 being exploited in your environment?
O3's eBPF runtime sensors and L7 egress monitoring detect and block the CVE-2023-40013 exploit chain at execution — protecting unpatched and end-of-life systems until the vendor patch is applied.