Bug 2416402 (CVE-2025-13470)

Summary: CVE-2025-13470 RNP: RNP: Confidentiality compromise due to uninitialized symmetric session key in Public-Key Encrypted Session Key (PKESK) packets
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: high Docs Contact:
Priority: high    
Version: unspecifiedCC: gotiwari, jgrulich, jhorak, mvyas, tpopela
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in RNP. This vulnerability allows for the trivial decryption of data encrypted using public-key encryption, fully compromising confidentiality, via an uninitialized symmetric session key in Public-Key Encrypted Session Key (PKESK) packets, which results in an all-zero byte array.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Bug Depends On: 2417031, 2417032, 2417033, 2417034, 2417035    
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Description OSIDB Bzimport 2025-11-21 18:01:18 UTC 
In RNP version 0.18.0 a refactoring regression causes the symmetric 
session key used for Public-Key Encrypted Session Key (PKESK) packets to
 be left uninitialized except for zeroing, resulting in it always being 
an all-zero byte array.

Any data encrypted using public-key encryption 
in this release can be decrypted trivially by supplying an all-zero 
session key, fully compromising confidentiality.

The vulnerability affects only public key encryption (PKESK packets).  Passphrase-based encryption (SKESK packets) is not affected.

Root cause: Vulnerable session key buffer used in PKESK packet generation.



The defect was introduced in commit `7bd9a8dc356aae756b40755be76d36205b6b161a` where initialization 
logic inside `encrypted_build_skesk()` only randomized the key for the 
SKESK path and omitted it for the PKESK path.