CVE-2020-26243
Published: 25 November 2020
Nanopb 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.
Priority
Status
Package | Release | Status |
---|---|---|
nanopb Launchpad, Ubuntu, Debian |
groovy |
Ignored
(end of life)
|
hirsute |
Not vulnerable
(0.4.4-1)
|
|
bionic |
Does not exist
|
|
focal |
Released
(0.4.1-1ubuntu0.1~esm1)
Available with Ubuntu Pro |
|
impish |
Not vulnerable
(0.4.4-1)
|
|
jammy |
Not vulnerable
(0.4.4-1)
|
|
kinetic |
Not vulnerable
(0.4.4-1)
|
|
lunar |
Not vulnerable
(0.4.4-1)
|
|
trusty |
Does not exist
|
|
upstream |
Released
(0.3.9.7, 0.4.4)
|
|
xenial |
Does not exist
|
|
mantic |
Not vulnerable
(0.4.4-1)
|
Severity score breakdown
Parameter | Value |
---|---|
Base score | 7.5 |
Attack vector | Network |
Attack complexity | Low |
Privileges required | None |
User interaction | None |
Scope | Unchanged |
Confidentiality | None |
Integrity impact | None |
Availability impact | High |
Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
References
- https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-26243
- https://github.com/nanopb/nanopb/security/advisories/GHSA-85rr-4rh9-hhwh
- https://github.com/nanopb/nanopb/commit/edf6dcbffee4d614ac0c2c1b258ab95185bdb6e9 (0.4.4)
- https://github.com/nanopb/nanopb/issues/615
- https://github.com/nanopb/nanopb/blob/2b48a361786dfb1f63d229840217a93aae064667/CHANGELOG.txt
- https://github.com/nanopb/nanopb/commit/4fe23595732b6f1254cfc11a9b8d6da900b55b0c
- https://ubuntu.com/security/notices/USN-6121-1
- NVD
- Launchpad
- Debian