vulnerability / NVI-00008967 / Revision 1
imgproxy has out-of-bounds heap read/write in ICO loader BMP header reconstruction that allows unauthenticated remote worker crash
GitHub lists this reviewed advisory for github.com/imgproxy/imgproxy/v3. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.
This report has not inspected your inventory, configuration, deployed build, reachability or evidence. A catalog listing and a severity score do not establish exposure or compromise.
01 / Meaning
Why it matters
Published affected context helps an owner decide what evidence to gather. This report has not examined your application.
7.5 high
GitHub source severity; exploitability and local consequence require separate evidence.
As of · GitHub Advisory Database
02 / Applicability
The affected context
Affected versions, configuration prerequisites and known exclusions are public. Confirm each one against the deployed service.
github.com/imgproxy/imgproxy/v3
source listed>= 3.3.0, < 4.0.17
### Summary Out-of-bounds heap write in imgproxy's ICO loader (`vips/icoload.c`): when the ICO entry's image data buffer is small, the loader's BMP-header-reconstruction writes land past the allocation, corrupting the size field of the following heap chunk. The worker then aborts deterministically (glibc `munmap_chunk(): invalid pointer` → SIGABRT → Go panic, exit code 2). ### Details In `vips_foreign_load_ico_header` in `vips/icoload.c`, after the ICO entry's image data is read into a heap buffer of `data_size + 14` bytes, the loader reconstructs a BMP file header in front of it using fields read from the ICO's internal BITMAPINFOHEADER: ``` uint32_t num_colors = GUINT32_FROM_LE(*(uint32_t *) (actual_data + 32)); // unvalidated uint16_t bpp = GUINT16_FROM_LE(*(uint16_t *) (actual_data + 14)); // unvalidated ``` ``` if ((num_colors == 0) && (bpp <= 8)) pix_offset = BMP_FILE_HEADER_LEN + BMP_BITMAP_INFO_HEADER_LEN + 4 * (1 << bpp); else pix_offset = BMP_FILE_HEADER_LEN + BMP_BITMAP_INFO_HEADER_LEN + 4 * num_colors; ``` ``` int32_t height = GINT32_FROM_LE(*(int32_t *) (actual_data + 8)); // readable past the buffer height = height / 2; ``` With a crafted entry d
03 / Response
What to do next
- investigate
Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.
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A fixed release is not deployment evidence.
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04 / Limits
What this report cannot establish
- Customer inventory, deployment, reachability and exploitation have not been inspected.
05 / Provenance
Sources you can inspect
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- GHSA-494m-4556-wf5p ↗
GitHub Advisory Database · vendor advisory
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Public revision history
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- Revision 1 ·
First indexed by Null; source disclosure date is shown separately.