CVE-2021-47877
Published: 21 January 2026
Summary
CVE-2021-47877 is a medium-severity Allocation of Resources Without Limits or Throttling (CWE-770) vulnerability in Geogebra (inferred from references). Its CVSS base score is 6.7 (Medium).
Operationally, exploitation aligns with the MITRE ATT&CK technique Application or System Exploitation (T1499.004); ranked at the 26.3th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
The strongest mitigations our analysis identified are NIST 800-53 SC-5 (Denial-of-service Protection) and SI-10 (Information Input Validation).
Deeper analysis
CVE-2021-47877 is a denial of service vulnerability in GeoGebra Graphing Calculator version 6.0.631.0. The flaw stems from inadequate handling of oversized input buffers, where attackers can input a payload of 8000 repeated characters into an input field, overwhelming the application and causing it to crash or become unresponsive. It is classified under CWE-770 (Allocation of Resources Without Limits or Throttling) with a CVSS v3.1 base score of 7.5 (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H).
The vulnerability can be exploited remotely by any unauthenticated attacker with low attack complexity and no user interaction required. Exploitation involves crafting and delivering the oversized character payload to the affected input field, resulting in high-impact denial of service that renders the graphing calculator application unusable.
Advisories and a proof-of-concept exploit are documented in references such as Exploit-DB (https://www.exploit-db.com/exploits/49653) and Vulncheck (https://www.vulncheck.com/advisories/geogebra-graphing-calculator-denial-of-service), with the official GeoGebra site at https://www.geogebra.org. No specific patch or mitigation details are outlined in the provided information.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-3645
Vulnerability details
GeoGebra Graphing Calculator 6.0.631.0 contains a denial of service vulnerability that allows attackers to crash the application by inputting an oversized buffer. Attackers can generate a payload of 8000 repeated characters to overwhelm the input field and cause the application…
more
to become unresponsive.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Direct mapping to application exploitation for endpoint DoS via oversized input causing crash (CWE-770 resource exhaustion).
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Restricts the amount and characteristics of information inputs to prevent oversized payloads from overwhelming input fields and causing denial of service.
Validates information inputs at entry points to reject oversized buffers that could lead to application crashes.
Provides denial-of-service protection mechanisms to limit the effects of oversized input attacks rendering the application unresponsive.