CVE-2020-5235

CVE-2020-5235 is a medium-severity vulnerability in Nanopb Project Nanopb with a CVSS 3.x base score of 6.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-125.

Key facts

Description

There is a potentially exploitable out of memory condition In Nanopb before 0.4.1, 0.3.9.5, and 0.2.9.4. When nanopb is compiled with PB_ENABLE_MALLOC, the message to be decoded contains a repeated string, bytes or message field and realloc() runs out of memory when expanding the array nanopb can end up calling `free()` on a pointer value that comes from uninitialized memory. Depending on platform this can result in a crash or further memory corruption, which may be exploitable in some cases. This problem is fixed in nanopb-0.4.1, nanopb-0.3.9.5, nanopb-0.2.9.4.

Frequently asked questions

What is CVE-2020-5235?
There is a potentially exploitable out of memory condition In Nanopb before 0.4.1, 0.3.9.5, and 0.2.9.4. When nanopb is compiled with PB_ENABLE_MALLOC, the message to be decoded contains a repeated string, bytes or message field and realloc() runs out of memory when expanding the array nanopb can end up calling `free()` on a pointer value that comes from uninitialized memory. Depending on platform this can result in a crash or further memory corruption, which may be exploitable in some cases. This problem is fixed in nanopb-0.4.1, nanopb-0.3.9.5, nanopb-0.2.9.4.
How severe is CVE-2020-5235?
CVE-2020-5235 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability low.
Is CVE-2020-5235 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (75th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-5235?
CVE-2020-5235 affects Nanopb Project Nanopb. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2020-5235?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2020-5235 published?
CVE-2020-5235 was published on 2020-02-04 and last updated on 2026-06-17.

References

Affected products (1)

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