CVE-2023-48703
HIGHRobotsAndPencils go-saml, a SAML client library written in Go, contains an authentication bypass vulnerability in all known versions. This is due to how the `xmlsec1` command line tool…
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
RobotsAndPencils go-saml, a SAML client library written in Go, contains an authentication bypass vulnerability in all known versions. This is due to how the xmlsec1 command line tool is called internally to verify the signature of SAML assertions. When xmlsec1 is used without defining the enabled key data, the origin of the public key for the signature verification is, unfortunately, not restricted. That means an attacker can sign the SAML assertions themselves and provide the required public key (e.g. an RSA key) directly embedded in the SAML token. Projects still using RobotsAndPencils/go-saml should move to another SAML library or alternatively remove support for SAML from their projects. The vulnerability can likely temporarily be fixed by forking the go-saml project and adding the command line argument --enabled-key-data and specifying a value such as x509 or raw-x509-cert when calling the xmlsec1 binary in the verify function. Please note that this workaround must be carefully tested before it can be used.
Affected Products
go-samlrobotsandpencilsDetection & mitigation playbook
Vendor / applianceDetect
Inventory every robotsandpencils go-saml 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-2023-48703 yet — track the robotsandpencils go-saml 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-2023-48703 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-2023-48703. 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-2023-48703 being exploited in your environment?
O3's eBPF runtime sensors and L7 egress monitoring detect and block the CVE-2023-48703 exploit chain at execution — protecting unpatched and end-of-life systems until the vendor patch is applied.