{"id":"CVE-2026-31883","state":"PUBLISHED","title":"FreeRDP has a `size_t` underflow in ADPCM decoder leads to heap-buffer-overflow write","description":"FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.24.0, a size_t underflow in the IMA-ADPCM and MS-ADPCM audio decoders leads to heap-buffer-overflow write via the RDPSND audio channel. In libfreerdp/codec/dsp.c, the IMA-ADPCM and MS-ADPCM decoders subtract block header sizes from a size_t variable without checking for underflow. When nBlockAlign (received from the server) is set such that size % block_size == 0 triggers the header parsing at a point where size is smaller than the header (4 or 8 bytes), the subtraction wraps size to ~SIZE_MAX. The while (size > 0) loop then continues for an astronomical number of iterations. This vulnerability is fixed in 3.24.0.","publishedAt":"2026-03-13T17:35:17.411Z","updatedAt":"2026-03-16T17:02:52.737Z","severity":{"score":6.5,"label":"Medium","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N","source":"GitHub_M"},"assigner":"GitHub_M","products":["FreeRDP FreeRDP"],"affected":[{"vendor":"FreeRDP","product":"FreeRDP","versions":[{"version":"< 3.24.0","status":"affected"}]}],"references":["https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-85x9-4xxp-xhm5","https://github.com/FreeRDP/FreeRDP/commit/16df2300e1e3f5a51f68fb1626429e58b531b7c8"],"weaknesses":["CWE-191","CWE-122"],"ingestedAt":"2026-10-29T20:11:40.391Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/31xxx/CVE-2026-31883.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-31883","state":"PUBLISHED","datePublished":"2026-03-13T17:35:17.411Z","dateUpdated":"2026-03-16T17:02:52.737Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-03-09T21:59:02.686Z"},"containers":{"cna":{"title":"FreeRDP has a `size_t` underflow in ADPCM decoder leads to heap-buffer-overflow write","descriptions":[{"lang":"en","value":"FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.24.0, a size_t underflow in the IMA-ADPCM and MS-ADPCM audio decoders leads to heap-buffer-overflow write via the RDPSND audio channel. In libfreerdp/codec/dsp.c, the IMA-ADPCM and MS-ADPCM decoders subtract block header sizes from a size_t variable without checking for underflow. When nBlockAlign (received from the server) is set such that size % block_size == 0 triggers the header parsing at a point where size is smaller than the header (4 or 8 bytes), the subtraction wraps size to ~SIZE_MAX. The while (size > 0) loop then continues for an astronomical number of iterations. This vulnerability is fixed in 3.24.0."}],"affected":[{"vendor":"FreeRDP","product":"FreeRDP","versions":[{"version":"< 3.24.0","status":"affected"}]}],"references":[{"url":"https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-85x9-4xxp-xhm5","name":"https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-85x9-4xxp-xhm5","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/FreeRDP/FreeRDP/commit/16df2300e1e3f5a51f68fb1626429e58b531b7c8","name":"https://github.com/FreeRDP/FreeRDP/commit/16df2300e1e3f5a51f68fb1626429e58b531b7c8","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":6.5,"baseSeverity":"MEDIUM","confidentialityImpact":"LOW","integrityImpact":"LOW","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-191","lang":"en","description":"CWE-191: Integer Underflow (Wrap or Wraparound)","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-122","lang":"en","description":"CWE-122: Heap-based Buffer Overflow","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-03-13T17:35:17.411Z"},"source":{"advisory":"GHSA-85x9-4xxp-xhm5","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","references":[{"url":"https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-85x9-4xxp-xhm5","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-03-16T17:02:49.465233Z","id":"CVE-2026-31883","options":[{"Exploitation":"poc"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-03-16T17:02:52.737Z"}}]}}}