https://cve.radiocsirt.org Contains only the most 10 recent entries. http://www.rssboard.org/rss-specification python-feedgen en Fri, 02 Oct 2026 20:10:27 +0000 https://cve.radiocsirt.org/vuln/cve-2025-67748 <p><strong>Affected:</strong> trailofbits fickling</p> <p>Fickling is a Python pickling decompiler and static analyzer. Versions prior to 0.1.6 had a bypass caused by `pty` missing from the block list of unsafe module imports. This led to unsafe pickles based on `pty.spawn()` being incorrectly flagged as `LIKELY_SAFE`, and was fixed in version 0.1.6. This impacted any user or system that used Fickling to vet pickle files for security issues.</p> <p><strong>Affected:</strong> trailofbits fickling</p> <p>Fickling is a Python pickling decompiler and static analyzer. Versions prior to 0.1.6 had a bypass caused by `pty` missing from the block list of unsafe module imports. This led to unsafe pickles based on `pty.spawn()` being incorrectly flagged as `LIKELY_SAFE`, and was fixed in version 0.1.6. This impacted any user or system that used Fickling to vet pickle files for security issues.</p> https://cve.radiocsirt.org/vuln/cve-2025-67748 https://cve.radiocsirt.org/vuln/ghsa-r7v6-mfhq-g3m2 <p><strong>Affected:</strong> PyPI: fickling</p> <p>## Fickling Assessment</p> <p>Based on the test case provided in the original report below, this bypass was caused by `pty` missing from our block list of unsafe module imports (as previously documented in #108), rather than the unused variable heuristic. This led to unsafe pickles based on `pty.spawn()` being incorrectly flagged as `LIKELY_SAFE`, and was fixed in https://github.com/trailofbits/fickling/pull/187.</p> <p>## Original report</p> <p>### Summary An unsafe deserialization vulnerability in Fickling allows a crafted pickle file to bypass the &#34;unused variable&#34; heuristic, enabling arbitrary code execution. This bypass is achieved by adding a trivial operation to the pickle file that &#34;uses&#34; the otherwise unused variable left on the stack after a malicious operation, tricking the detection mechanism into classifying the file as safe.</p> <p>### Details Fickling relies on the heuristic of detecting unused variables in the VM&#39;s stack after execution. Opcodes like `REDUCE`, `OBJ`, and `INST`, which can be used for arbitrary code execution, leave a value on the stack that is often unused in malicious pickle files. This vulnerability enables a bypass by modifying the pickle file to use this leftover variable. A simple way to achieve this is to add a `BUILD` opcode that, in effect, adds a `__setstate__` to the unused variable. This makes Fickling consider the variable &#34;used,&#34; thus failing to flag the malicious file.</p> <p>### PoC The following is a disassembled view of a malicious pickle file that bypas…</p> <p><strong>Affected:</strong> PyPI: fickling</p> <p>## Fickling Assessment</p> <p>Based on the test case provided in the original report below, this bypass was caused by `pty` missing from our block list of unsafe module imports (as previously documented in #108), rather than the unused variable heuristic. This led to unsafe pickles based on `pty.spawn()` being incorrectly flagged as `LIKELY_SAFE`, and was fixed in https://github.com/trailofbits/fickling/pull/187.</p> <p>## Original report</p> <p>### Summary An unsafe deserialization vulnerability in Fickling allows a crafted pickle file to bypass the &#34;unused variable&#34; heuristic, enabling arbitrary code execution. This bypass is achieved by adding a trivial operation to the pickle file that &#34;uses&#34; the otherwise unused variable left on the stack after a malicious operation, tricking the detection mechanism into classifying the file as safe.</p> <p>### Details Fickling relies on the heuristic of detecting unused variables in the VM&#39;s stack after execution. Opcodes like `REDUCE`, `OBJ`, and `INST`, which can be used for arbitrary code execution, leave a value on the stack that is often unused in malicious pickle files. This vulnerability enables a bypass by modifying the pickle file to use this leftover variable. A simple way to achieve this is to add a `BUILD` opcode that, in effect, adds a `__setstate__` to the unused variable. This makes Fickling consider the variable &#34;used,&#34; thus failing to flag the malicious file.</p> <p>### PoC The following is a disassembled view of a malicious pickle file that bypas…</p> https://cve.radiocsirt.org/vuln/ghsa-r7v6-mfhq-g3m2