An integer overflow in a specified pitch and buffer-size computation leads to a heap out-of-bounds write when Orthanc DICOM Server decodes an attacker-supplied PNG.

A security flaw has been discovered in Orthanc DICOM Server up to 1.12.11. This issue affects the function DcmItem::read of the file OrthancFramework/Sources/DicomParsing/FromDcmtkBridge.cpp of the component DCMTK Parser. Performing a manipulation results in stack-based buffer overflow. Attacking locally is a requirement. The exploit has been released to the public and may be used for attacks. The patch is named bae99026ca97. To fix this issue, it is recommended to deploy a patch.

A weakness has been identified in Orthanc Explorer 2 up to 1.12.0. The impacted element is an unknown function of the file WebApplication/src/components/StudyList.vue of the component URL Handler. This manipulation of the argument remote-source causes cross site scripting. It is possible to initiate the attack remotely. The exploit has been made available to the public and could be used for attacks. Patch name: 21f78ce5da668bf5233efcd1896ec7c6e3b22eae. Applying a patch is the recommended action to fix this issue.

A memory exhaustion vulnerability exists in ZIP archive processing. Orthanc automatically extracts ZIP archives uploaded to certain endpoints and trusts metadata fields describing the uncompressed size of archived files. An attacker can craft a small ZIP archive containing a forged size value, causing the server to allocate extremely large buffers during extraction.

A gzip decompression bomb vulnerability exists when Orthanc processes HTTP request with Content-Encoding: gzip. The server does not enforce limits on decompressed size and allocates memory based on attacker-controlled compression metadata. A specially crafted gzip payload can trigger excessive memory allocation and exhaust system memory.

A heap buffer overflow vulnerability exists in the PAM image parsing logic. When Orthanc processes a crafted PAM image embedded in a DICOM file, image dimensions are multiplied using 32-bit unsigned arithmetic. Specially chosen values can cause an integer overflow during buffer size calculation, resulting in the allocation of a small buffer followed by a much larger write operation during pixel processing.

Orthanc server prior to version 1.5.8 does not enable basic authentication by default when remote access is enabled. This could result in unauthorized access by an attacker.