CVE-2025-56352
41Vexday Risk Score
No sign of exploitation. It has a public proof of concept.
ssvc Attendcvss 7.5epss 0.3%
exploitation probability
0.3%top 80% of all CVEs
observed exploitation
nono source reports it
1 public exploit(s)
In tinyMQTT commit 6226ade15bd4f97be2d196352e64dd10937c1962 (2024-02-18), the broker mishandles protocol violations during CONNECT packet parsing. When receiving a CONNECT packet with a zero-length Client ID while CleanSession is set to 0, the broker correctly replies with a CONNACK return code 0x02 (Identifier Rejected) but fails to explicitly close the TCP connection. Since the surrounding connection teardown logic is not guaranteed to execute, each such invalid CONNECT attempt leaves the underlying socket open. Repeated attempts cause server-side resource exhaustion due to accumulating file descriptors and memory usage, potentially resulting in denial of service.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Affected products
n/a · n/apublic PoCs found — 1
cve_referencegithub.com/user-attachments/files/21207896/Resource_Exhaustion_Poc.txtunverified⚠ Public resources, to assess the exposure of systems you control or are authorized to test. Test only with authorization.