CVE-2011-1136

Tesseract 5.5.3 and earlier contains a flaw in Plumbing::DeSerialize that accepts a zero-length stack for NT_SERIES, NT_PARALLEL, or NT_REVERSED layers in a crafted .traineddata model. During LSTMRecognizer initialization, CacheXScaleFactor dereferences stack_[0] on the empty vector and invokes a virtual method through an invalid Network pointer.

Tesseract version 5.5.3 and earlier contains a heap overflow vulnerability in Classify::ReadIntTemplates, which reads NumClassPruners, NumClasses, and NumProtoSets from a .traineddata file without validating them against MAX_* limits. Oversized values cause out-of-bounds pointer writes on the heap during classifier initialization.

Tesseract version 5.5.3 and earlier contains a heap overflow vulnerability in UNICHARSET::load_via_fgets, which trusts the declared unichar count as a loop bound and uses id as an unchecked index into the unichars vector. This can lead to out-of-bounds writes during initialization.

Tesseract version 5.5.3 and earlier contains a heap overflow vulnerability in GenericVector::read, which reads reserved and size_used_ fields from a .traineddata file without caps. A crafted file can set reserved to a small value and size_used_ to a large value, causing out-of-bounds writes of FontInfo structures.

In Tesseract version 5.5.3 and earlier, RecodedCharID::DeSerialize in src/ccutil/unicharcompress.h validates length_ but accepts negative code_ values from a crafted .traineddata recoder component. UnicharCompress::ComputeCodeRange can consequently produce code_range_ equal to zero, after which SetupDecoder indexes is_valid_start_ with the negative code on a size-zero vector, causing an out-of-bounds bit write and a crash or allocation failure. No fixed release is available.

Tesseract 5.5.3 and earlier fails to validate dimension consistency in NetworkIO::WriteTimeStepPart and NetworkIO::AddTimeStepPart. A crafted .traineddata file with an NT_LSTM layer can cause a heap out-of-bounds write during the first recognition step on the default LSTM engine. No fixed release is available.

Tesseract 5.5.3 and earlier does not validate the deserialized scalars ni_ and no_ against weight-matrix dimensions in FullyConnected::DeSerialize. A crafted .traineddata file with an NT_SOFTMAX layer can cause a heap out-of-bounds write and read on the default LSTM engine. No fixed release is available.

Tesseract 5.5.3 and earlier, in Classify::ReadNormProtos, extracts a whitespace-delimited token from a .traineddata file into a fixed 61-byte stack buffer without setting stream width. A token longer than 60 characters writes up to 39 attacker-controlled bytes past the buffer during TessBaseAPI::Init of the legacy engine. No fixed release is available.

Tesseract is an open source OCR engine. Prior to 5.5.3, a crafted .traineddata model loaded through TessBaseAPI::Init can cause SquishedDawg::read_squished_dawg in src/dict/dawg.cpp to accept an unterminated forward-edge run, after which SquishedDawg::Load calls num_forward_edges(0) and last_edge in src/dict/dawg.h reads beyond edges_, causing a heap out-of-bounds read and process crash before image processing. This issue is fixed in version 5.5.3.

Tesseract is an open source OCR engine. Prior to 5.5.3, a crafted .traineddata LSTM model component loaded through Tesseract's deserializer can cause an unchecked signed integer multiplication in Convolve::DeSerialize in src/lstm/convolve.cpp to wrap the convolution output-channel count, undersizing the forward-pass output buffer while writes use the unwrapped element count and causing a heap out-of-bounds write during OCR recognition. This issue is fixed in version 5.5.3.