CVE-2021-32703
Published: 12 July 2021
Summary
CVE-2021-32703 is a medium-severity Improper Control of Interaction Frequency (CWE-799) vulnerability in Nextcloud Nextcloud Server. Its CVSS base score is 5.3 (Medium).
Operationally, ranked in the top 31.4% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2021-19499
Vulnerability details
Nextcloud Server is a Nextcloud package that handles data storage. In versions prior to 19.0.13, 20.011, and 21.0.3, there was a lack of ratelimiting on the shareinfo endpoint. This may have allowed an attacker to enumerate potentially valid share tokens.…
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The issue was fixed in versions 19.0.13, 20.0.11, and 21.0.3. There are no known workarounds.
- CWE(s)
Related Threats
No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.
Affected Assets
Mitigating Controls
Likely Mitigating Controls AI
Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.
This control directly enforces limits on consecutive invalid logon attempts and automatic response (e.g., lockout) to prevent brute-force exploitation of authentication mechanisms.
Specific conditions can include excessive failed attempts, triggering stronger authentication that restricts brute-force exploitation.
The control requires defining frequency, timing, and approval for security interactions, directly addressing uncontrolled interaction rates.
Allocation policies inherently restrict interaction frequency, reducing the impact of excessive requests.
Spam protection explicitly controls interaction frequency by detecting and acting on bulk unsolicited messages from external sources.