Fixes CVE-2025-2757: Heap-based Buffer Overflow in AI_MD5_PARSE_STRING_IN_QUOTATION (closes #6019)

[VinzSpring]

Closes #6019
description:

• heap buffer overflow in AI_MD5_PARSE_STRING_IN_QUOTATION. An attacker could potentially exploit the vulnerability to cause a remote code execution, if they can trick the victim into running assimp on a malformed MD5 file

fix:

• truncated the string to the maximum supported length, mitigating overflow

fuzz results after fix:

sh /home/ubuntu/assimp/test_exploits/CVE-2025-2757.sh
-- Shared libraries disabled
-- GCC13 detected disabling "-Wdangling-reference" in Cpp files as it appears to be a false positive
-- compiling zlib from sources
-- GCC13 detected disabling "-Warray-bounds and -Wstringop-overflow" for AssetLib/MDL/MDLLoader.cpp as it appears to be a false positive
-- VRML disabled
-- tinyusdz disabled
-- Enabled importer formats: AMF 3DS AC ASE ASSBIN B3D BVH COLLADA DXF CSM HMP IRRMESH IQM IRR LWO LWS MD2 MD3 MD5 MDC MDL NFF NDO OFF OBJ OGRE OPENGEX PLY MS3D COB BLEND IFC XGL FBX Q3D Q3BSP RAW SIB SMD STL TERRAGEN 3D X X3D GLTF 3MF MMD
-- Disabled importer formats: USD
-- Enabled exporter formats: OBJ OPENGEX PLY 3DS ASSBIN ASSXML COLLADA FBX STL X X3D GLTF 3MF PBRT ASSJSON STEP
-- Disabled exporter formats:
-- Treating all warnings as errors (for assimp library only)
-- Configuring done (0.0s)
-- Generating done (0.0s)
-- Build files have been written to: /home/ubuntu/assimp
[2/2] Linking CXX static library lib/libassimp.a
INFO: Running with entropic power schedule (0xFF, 100).
INFO: Seed: 3917044551
INFO: Loaded 1 modules (7 inline 8-bit counters): 7 [0x6505c7ea5a30, 0x6505c7ea5a37),
INFO: Loaded 1 PC tables (7 PCs): 7 [0x6505c7ea5a38,0x6505c7ea5aa8),
./assimp_fuzzer: Running 1 inputs 1 time(s) each.
Running: ./crash
Executed ./crash in 4 ms
NOTE: fuzzing was not performed, you have only

•   executed the target code on a fixed set of inputs.*
  

[tellypresence]

Please add text "Closes #6019" in description of PR so github will associate PR with issue

[kimkulling]

Looks fine, thanks for the help.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[kimkulling]

Merged, thanks a lot for your contribution.