CVE-2020-26243

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Summary

CVECVE-2020-26243
StatePUBLIC
Assigner[email protected]
Source PriorityCVE Program / NVD first with legacy fallback
Published2020-11-25 17:15:00 UTC
Updated2020-12-07 20:49:00 UTC
DescriptionNanopb is a small code-size Protocol Buffers implementation. In Nanopb before versions 0.4.4 and 0.3.9.7, decoding specifically formed message can leak memory if dynamic allocation is enabled and an oneof field contains a static submessage that contains a dynamic field, and the message being decoded contains the submessage multiple times. This is rare in normal messages, but it is a concern when untrusted data is parsed. This is fixed in versions 0.3.9.7 and 0.4.4. The following workarounds are available: 1) Set the option `no_unions` for the oneof field. This will generate fields as separate instead of C union, and avoids triggering the problematic code. 2) Set the type of the submessage field inside oneof to `FT_POINTER`. This way the whole submessage will be dynamically allocated and the problematic code is not executed. 3) Use an arena allocator for nanopb, to make sure all memory can be released afterwards.

Risk And Classification

Problem Types: CWE-119 | CWE-20

NVD Known Affected Configurations (CPE 2.3)

TypeVendorProductVersionUpdateEditionLanguage
Application Nanopb Project Nanopb All All All All
Application Nanopb Project Nanopb All All All All

References

ReferenceSourceLinkTags
Memory leak when parsing a protobuf message with duplicate fields · Issue #615 · nanopb/nanopb · GitHub MISC github.com Exploit, Patch, Third Party Advisory
Fix memory leak with oneofs and PB_ENABLE_MALLOC (#615) · nanopb/nanopb@4fe2359 · GitHub MISC github.com Patch, Third Party Advisory
Oneof fields with PB_ENABLE_MALLOC can leak memory · Advisory · nanopb/nanopb · GitHub CONFIRM github.com Third Party Advisory
nanopb/CHANGELOG.txt at 2b48a361786dfb1f63d229840217a93aae064667 · nanopb/nanopb · GitHub MISC github.com Release Notes, Third Party Advisory
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Legacy QID Mappings

  • 199489 Ubuntu Security Notification for Nanopb Vulnerabilities (USN-6121-1)
  • 983222 Python (pip) Security Update for nanopb (GHSA-85rr-4rh9-hhwh)
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