ZeroHour
Schneier on Securitypublished ()ingested Bruce Schneier

Breaking RSA through Insufficiently Random Primes

Vulnerabilities mentionedAll →

CVEVulnerabilityCVSSEPSSFlagsAffectedExposurePublished
CVE-2022-26351
Rejected reason: DO NOT USE THIS CANDIDATE NUMBER.

Rejected reason: DO NOT USE THIS CANDIDATE NUMBER. ConsultIDs: CVE-2022-26320. Reason: This candidate is a reservation duplicate of CVE-2022-26320. Notes: All CVE users should reference CVE-2022-26320 instead of this candidate. All references and descriptions in this candidate have been removed to prevent accidental usage

NVD description · AI analysis pending
Full article179 words · extracted from schneier.com · click to collapse

Basically, the SafeZone library doesn’t sufficiently randomize the two prime numbers it used to generate RSA keys. They’re too close to each other, which makes them vulnerable to recovery.

There aren’t many weak keys out there, but there are some:

So far, Böck has identified only a handful of keys in the wild that are vulnerable to the factorization attack. Some of the keys are from printers from two manufacturers, Canon and Fujifilm (originally branded as Fuji Xerox). Printer users can use the keys to generate a Certificate Signing Request. The creation date for the all the weak keys was 2020 or later. The weak Canon keys are tracked as CVE-2022-26351.

Böck also found four vulnerable PGP keys, typically used to encrypt email, on SKS PGP key servers. A user ID tied to the keys implied they were created for testing, so he doesn’t believe they’re in active use.

Tags: cryptanalysis, keys, PGP, random numbers, RSA

Posted on March 16, 2022 at 11:35 AM13 Comments

Sidebar photo of Bruce Schneier by Joe MacInnis.

Text extracted automatically; images, tables and formatting may be missing. Original: https://www.schneier.com/blog/archives/2022/03/breaking-rsa-through-insufficiently-random-primes.html