CVE-2021-23839
published 2021-02-16CVE-2021-23839: OpenSSL 1.0.2 supports SSLv2. If a client attempts to negotiate SSLv2 with a server that is configured to support both SSLv2 and more recent SSL and TLS…
PriorityP419low3.7CVSS 3.1
AVNACHPRNUINSUCNILAN
EPSS
2.96%
85.8th percentile
OpenSSL 1.0.2 supports SSLv2. If a client attempts to negotiate SSLv2 with a server that is configured to support both SSLv2 and more recent SSL and TLS versions then a check is made for a version rollback attack when unpadding an RSA signature. Clients that support SSL or TLS versions greater than SSLv2 are supposed to use a special form of padding. A server that supports greater than SSLv2 is supposed to reject connection attempts from a client where this special form of padding is present, because this indicates that a version rollback has occurred (i.e. both client and server support greater than SSLv2, and yet this is the version that is being requested). The implementation of this padding check inverted the logic so that the connection attempt is accepted if the padding is present, and rejected if it is absent. This means that such as server will accept a connection if a version rollback attack has occurred. Further the server will erroneously reject a connection if a normal SSLv2 connection attempt is made. Only OpenSSL 1.0.2 servers from version 1.0.2s to 1.0.2x are affected by this issue. In order to be vulnerable a 1.0.2 server must: 1) have configured SSLv2 support at compile time (this is off by default), 2) have configured SSLv2 support at runtime (this is off by default), 3) have configured SSLv2 ciphersuites (these are not in the default ciphersuite list) OpenSSL 1.1.1 does not have SSLv2 support and therefore is not vulnerable to this issue. The underlying error is in the implementation of the RSA_padding_check_SSLv23() function. This also affects the RSA_SSLV23_PADDING padding mode used by various other functions. Although 1.1.1 does not support SSLv2 the RSA_padding_check_SSLv23() function still exists, as does the RSA_SSLV23_PADDING padding mode. Applications that directly call that function or use that padding mode will encounter this issue. However since there is no support for the SSLv2 protocol in 1.1.1 this is considered a bug and not a secur
Affected
21 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| debian | openssl | < openssl 1.0.0d-1 (bookworm) | openssl 1.0.0d-1 (bookworm) |
| openssl | openssl | — | — |
| openssl | openssl | >= 0 < 1.0.0d-1 | 1.0.0d-1 |
| openssl | openssl | >= 0 < 1.0.0d-1 | 1.0.0d-1 |
| openssl | openssl | >= 0 < 1.0.0d-1 | 1.0.0d-1 |
| openssl | openssl | >= 0 < 1.0.0d-1 | 1.0.0d-1 |
| openssl | openssl | 1.0.2s – 1.0.2x | — |
| oracle | business_intelligence | — | — |
| oracle | business_intelligence | — | — |
| oracle | business_intelligence | — | — |
| oracle | business_intelligence | — | — |
| oracle | enterprise_manager_for_storage_management | — | — |
| oracle | enterprise_manager_ops_center | — | — |
| oracle | graalvm | — | — |
| oracle | graalvm | — | — |
| oracle | graalvm | — | — |
| oracle | jd_edwards_world_security | — | — |
| oracle | zfs_storage_appliance_kit | — | — |
| paloalto | cortex_xdr | — | — |
| siemens | sinec_ins | < 1.0 | 1.0 |
| siemens | sinec_ins | — | — |
CVSS provenance
nvdv3.13.7LOWCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N
nvdv2.04.3MEDIUMAV:N/AC:M/Au:N/C:N/I:P/A:N
osv3.7LOW
vendor_debian3.7LOW
vendor_redhat3.7LOW
Stop checking back — get the weekly exploitation signal.
Every Monday: what got weaponized or added to CISA KEV in the last seven days — each CVE cross-linked to its PoC, Nuclei template, and detection rule. Free, one email a week, unsubscribe in one click.
Palo Alto
PAN-SA-2024-0014 Informational Bulletin: Impact of OSS CVEs in Cortex XDR Agent
vendor_paloalto·2024-11-07·CVSS 6.8
CVE-2014-0195 [MEDIUM] PAN-SA-2024-0014 Informational Bulletin: Impact of OSS CVEs in Cortex XDR Agent
PAN-SA-2024-0014 Informational Bulletin: Impact of OSS CVEs in Cortex XDR Agent
The Palo Alto Networks Product Security Assurance team has evaluated the following open source software (OSS) CVEs as they relate to Cortex XDR Agent. While Cortex XDR Agent may include the
CVEs: CVE-2014-0195, CVE-2014-0224, CVE-2014-3509, CVE-2014-3512, CVE-2014-3513, CVE-2014-3567, CVE-2015-0209, CVE-2015-0292, CVE-2015-1789, CVE-2015-1791, CVE-2015-1793, CVE-2015-3194, CVE-2016-0705, CVE-2016-0797, CVE-2016-0798, CVE-2016-0799, CVE-2016-2105, CVE-2016-2106, CVE-2016-2108, CVE-2016-2109, CVE-2016-2176, CVE-2016-2177, CVE-2016-2179, CVE-2016-2180, CVE-2016-2181, CVE-2016-2182, CVE-2016-2183, CVE-2016-6302, CVE-2016-6303, CVE-2016-6304, CVE-2019-1551, CVE-2019-1552, CVE-2019-1559, CVE-2019-1563, CVE-2020-196
CISA ICS
Siemens SINEC INS
cisa_ics·2022-09-15·CVSS 7.8
[HIGH] Siemens SINEC INS
## Archived Content In an effort to keep CISA.gov current, the archive contains outdated information that may not reflect current policy or programs.
ICS Advisory
##
Siemens SINEC INS
Last RevisedSeptember 15, 2022
Alert CodeICSA-22-258-05
## 1. EXECUTIVE SUMMARY
- CVSS v3 8.8
- ATTENTION: Exploitable remotely/Low attack complexity
- Vendor: Siemens
- Equipment: SINEC INS
- Vulnerabilities: Improper Input Validation, Integer Overflow or Wraparound, Uncontrolled Resource Consumption, Command Injection, Inadequate Encryption Strength, Missing Encryption of Sensitive Data, Improper Restriction of Operations Within the Bounds of a Memory Buffer, Exposure of Private Personal Information to an Unauthorized Actor, Open Redirect, Improper Resour
Red Hat
openssl: incorrect SSLv2 rollback protection
vendor_redhat·2021-02-16·CVSS 3.7
CVE-2021-23839 [LOW] openssl: incorrect SSLv2 rollback protection
openssl: incorrect SSLv2 rollback protection
OpenSSL 1.0.2 supports SSLv2. If a client attempts to negotiate SSLv2 with a server that is configured to support both SSLv2 and more recent SSL and TLS versions then a check is made for a version rollback attack when unpadding an RSA signature. Clients that support SSL or TLS versions greater than SSLv2 are supposed to use a special form of padding. A server that supports greater than SSLv2 is supposed to reject connection attempts from a client where this special form of padding is present, because this indicates that a version rollback has occurred (i.e. both client and server support greater than SSLv2, and yet this is the version that is being requested). The implementation of this padding check inverted the logic so that the connection at
Debian
CVE-2021-23839: openssl - OpenSSL 1.0.2 supports SSLv2. If a client attempts to negotiate SSLv2 with a ser...
vendor_debian·2021·CVSS 3.7
CVE-2021-23839 [LOW] CVE-2021-23839: openssl - OpenSSL 1.0.2 supports SSLv2. If a client attempts to negotiate SSLv2 with a ser...
OpenSSL 1.0.2 supports SSLv2. If a client attempts to negotiate SSLv2 with a server that is configured to support both SSLv2 and more recent SSL and TLS versions then a check is made for a version rollback attack when unpadding an RSA signature. Clients that support SSL or TLS versions greater than SSLv2 are supposed to use a special form of padding. A server that supports greater than SSLv2 is supposed to reject connection attempts from a client where this special form of padding is present, because this indicates that a version rollback has occurred (i.e. both client and server support greater than SSLv2, and yet this is the version that is being requested). The implementation of this padding check inverted the logic so that the connection attempt is accepted if the padding is present, a
GHSA
GHSA-rh82-fhxg-rxx8: OpenSSL 1
ghsa_unreviewed·2022-05-24
CVE-2021-23839 [HIGH] CWE-326 GHSA-rh82-fhxg-rxx8: OpenSSL 1
OpenSSL 1.0.2 supports SSLv2. If a client attempts to negotiate SSLv2 with a server that is configured to support both SSLv2 and more recent SSL and TLS versions then a check is made for a version rollback attack when unpadding an RSA signature. Clients that support SSL or TLS versions greater than SSLv2 are supposed to use a special form of padding. A server that supports greater than SSLv2 is supposed to reject connection attempts from a client where this special form of padding is present, because this indicates that a version rollback has occurred (i.e. both client and server support greater than SSLv2, and yet this is the version that is being requested). The implementation of this padding check inverted the logic so that the connection attempt is accepted if the padding is present, a
OSV
CVE-2021-23839: OpenSSL 1
osv·2021-02-16·CVSS 3.7
CVE-2021-23839 [LOW] CVE-2021-23839: OpenSSL 1
OpenSSL 1.0.2 supports SSLv2. If a client attempts to negotiate SSLv2 with a server that is configured to support both SSLv2 and more recent SSL and TLS versions then a check is made for a version rollback attack when unpadding an RSA signature. Clients that support SSL or TLS versions greater than SSLv2 are supposed to use a special form of padding. A server that supports greater than SSLv2 is supposed to reject connection attempts from a client where this special form of padding is present, because this indicates that a version rollback has occurred (i.e. both client and server support greater than SSLv2, and yet this is the version that is being requested). The implementation of this padding check inverted the logic so that the connection attempt is accepted if the padding is present, a
No detection rules found.
https://cert-portal.siemens.com/productcert/pdf/ssa-637483.pdfhttps://git.openssl.org/gitweb/?p=openssl.git%3Ba=commitdiff%3Bh=30919ab80a478f2d81f2e9acdcca3fa4740cd547https://kb.pulsesecure.net/articles/Pulse_Security_Advisories/SA44846https://security.netapp.com/advisory/ntap-20210219-0009/https://security.netapp.com/advisory/ntap-20240621-0006/https://www.openssl.org/news/secadv/20210216.txthttps://www.oracle.com//security-alerts/cpujul2021.htmlhttps://www.oracle.com/security-alerts/cpuApr2021.htmlhttps://www.oracle.com/security-alerts/cpuapr2022.htmlhttps://www.oracle.com/security-alerts/cpuoct2021.htmlhttps://cert-portal.siemens.com/productcert/pdf/ssa-637483.pdfhttps://git.openssl.org/gitweb/?p=openssl.git%3Ba=commitdiff%3Bh=30919ab80a478f2d81f2e9acdcca3fa4740cd547https://kb.pulsesecure.net/articles/Pulse_Security_Advisories/SA44846https://security.netapp.com/advisory/ntap-20210219-0009/https://security.netapp.com/advisory/ntap-20240621-0006/https://www.openssl.org/news/secadv/20210216.txthttps://www.oracle.com//security-alerts/cpujul2021.htmlhttps://www.oracle.com/security-alerts/cpuApr2021.htmlhttps://www.oracle.com/security-alerts/cpuapr2022.htmlhttps://www.oracle.com/security-alerts/cpuoct2021.html
2021-02-16
Published