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OpenSSL官网安全更新(2021-02-16)

来源:OpenSSL官网 发布日期:2021-02-16 阅读次数:3168 评论:0

基本信息

发布日期:2021-02-16(官方当地时间)

更新类型:安全更新

更新版本:未知

感知时间:2021-02-17 00:14:08

风险等级:低危

情报贡献:TSRC

更新标题

安全更新

更新详情

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
security issue in that version.

OpenSSL 1.0.2 is out of support and no longer receiving public updates. Premium
support customers of OpenSSL 1.0.2 should upgrade to 1.0.2y. Other users should
upgrade to 1.1.1j. Reported by D. Katz and Joel Luellwitz (Trustwave).

软件描述

OpenSSL是一个开放源代码的软件库包,应用程序可以使用这个包来进行安全通信,避免窃听,同时确认另一端连接者的身份

CVE编号

TSRC分析

暂无

业界资讯

暂无

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