Summary
Knative Serving vulnerable to attacker-controlled pod causing denial of service of autoscaler
A vulnerability was fond in Knative Serving that could allow an attacker to crash the Knative Serving autoscaler resulting in a denial of service. The attacker would need to have compromised one pod in the Knative Serving deployment, and with that position they could launch the attack against the autoscaler.
When the autoscaler scrapes the metrics of pods, it sends a request to the /metrics endpoint of each pod and reads the response. The attacker would need to detect the request from the autoscaler to the /metrics endpoint of the pod they had compromised and send a malicious response back to the autoscaler. At this point, the autoscaler would crash. The root cause of the vulnerability was a memory exhaustion issue in the autoscaler that the attacker could trigger with the malicious reponse.
The vulnerability would allow a privilege escalation by the attacker from controlling one point to having negative impact on the entire Knative Serving deployment.
Mitigation
The vulnerability has been patched in v1.10.5, v1.11.3 and v1.12.0
Credits
The vulnerability was reported by Ada Logics during an ongoing security audit of Knative involving Ada Logics, the Knative maintainers, OSTIF and CNCF.
Impact
All users are vulnerable to this; Users that have not had any of their pods compromised are not at risk of this vulnerability.
Crafted input forces the application to consume excessive CPU, memory, or other resources, degrading or denying service. Typical impact: denial of service.
CVE-2023-48713 has a CVSS score of 5.3 (Medium). The vector is network-reachable, low privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (0.39.0); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
Already deployed Kodem?
See it in your environmentNew to Kodem? Get a demo →Remediation advice
Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.
Frequently Asked Questions
- What is CVE-2023-48713? CVE-2023-48713 is a medium-severity uncontrolled resource consumption vulnerability in knative.dev/serving (go), affecting versions < 0.39.0. It is fixed in 0.39.0. Crafted input forces the application to consume excessive CPU, memory, or other resources, degrading or denying service.
- How severe is CVE-2023-48713? CVE-2023-48713 has a CVSS score of 5.3 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of knative.dev/serving are affected by CVE-2023-48713? knative.dev/serving (go) versions < 0.39.0 is affected.
- Is there a fix for CVE-2023-48713? Yes. CVE-2023-48713 is fixed in 0.39.0. Upgrade to this version or later.
- Is CVE-2023-48713 exploitable, and should I be worried? Whether CVE-2023-48713 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2023-48713 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2023-48713? Upgrade
knative.dev/servingto 0.39.0 or later.