CVE-2020-26939 json
Observable Differences in Behavior to Error Inputs in Bouncy Castle
published 6y ago modified 4mo ago also GHSA-72m5-fvvv-55m6 , EUVD-2021-0779
- cvss
- 5.3
- version 3.1, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.9%
- EPSS 0.9% chance of exploitation in 30 days, percentile 60%
- public exploits
- 0
- none known
Summary
In Legion of the Bouncy Castle BC before 1.61 and BC-FJA before 1.0.1.2, attackers can obtain sensitive information about a private exponent because of Observable Differences in Behavior to Error Inputs. This occurs in org.bouncycastle.crypto.encodings.OAEPEncoding. Sending invalid ciphertext that decrypts to a short payload in the OAEP Decoder could result in the throwing of an early exception, potentially leaking some information about the private exponent of the RSA private key performing the encryption.
Patch / fix
- maven org.bouncycastle:bcprov-jdk14 1.61
- maven org.bouncycastle:bcprov-jdk15 1.61
- maven org.bouncycastle:bcprov-jdk16 1.61
- maven org.bouncycastle:bc-fips 1.0.2
- maven org.bouncycastle:bcprov-ext-jdk15on 1.61
- maven org.bouncycastle:bcprov-ext-jdk16 1.61
- maven org.bouncycastle:bcprov-jdk15on 1.61
- maven org.bouncycastle:bcprov-jdk15to18 1.61
- bouncycastle fips_java_api 1.0.1.2
- bouncycastle legion-of-the-bouncy-castle 1.61
- bouncycastle Debian 14, Debian 13, Debian 12 1.61-1
debian advisories DEBIAN-CVE-2020-26939
Is CVE-2020-26939 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.
Check with FencerExploit prediction
0.93% chance of exploitation in the next 30 days, higher than 60% of all scored CVEs (FIRST EPSS, 2026-11-09).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| NVD | 3.1 | 5.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N |
| NVD | 2.0 | 5.0 | AV:N/AC:L/Au:N/C:P/I:N/A:N |
| GitHub | 3.1 | 5.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| maven | org.bouncycastle:bcprov-jdk14 | <1.61 |
1.61 |
| maven | org.bouncycastle:bcprov-jdk15 | <1.61 |
1.61 |
| maven | org.bouncycastle:bcprov-jdk16 | <1.61 |
1.61 |
| maven | org.bouncycastle:bc-fips | <1.0.2 |
1.0.2 |
| maven | org.bouncycastle:bcprov-ext-jdk15on | <1.61 |
1.61 |
| maven | org.bouncycastle:bcprov-ext-jdk16 | <1.61 |
1.61 |
| maven | org.bouncycastle:bcprov-jdk15on | <1.61 |
1.61 |
| maven | org.bouncycastle:bcprov-jdk15to18 | <1.61 |
1.61 |
Classification
- Weakness
-
- CWE-203 Observable Discrepancy
References
-
github.com
/bcgit/bc-java/wiki/CVE-2020-26939
web, patch, third-party-advisory
-
github.com
/bcgit/bc-java/commit/930f8b274c4f1f3a46e68b5441f1e7fadb57e8c1
web
-
lists.apache.org
/thread.html/r8c36ba34e80e05eecb1f80071cc834d705616f315b634ec0c7d8f42e%40%3Cissues.solr.apache.org%3E
mailing-list, web
-
nvd.nist.gov
/vuln/detail/CVE-2020-26939
advisory
-
lists.apache.org
/thread.html/r8c36ba34e80e05eecb1f80071cc834d705616f315b634ec0c7d8f42e@%3Cissues.solr.apache.org%3E
web
-
lists.debian.org
/debian-lts-announce/2020/11/msg00007.html
web
-
security.netapp.com
/advisory/ntap-20201202-0005
web
Sources
- CVE List CVE-2020-26939
- GitHub Advisory GHSA-72m5-fvvv-55m6
- NVD CVE-2020-26939
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