Debian DLA-2773-1 : curl - LTS security update

high Nessus Plugin ID 153845

Synopsis

The remote Debian host is missing one or more security-related updates.

Description

The remote Debian 9 host has packages installed that are affected by multiple vulnerabilities as referenced in the dla-2773 advisory.

- A user can tell curl >= 7.20.0 and <= 7.78.0 to require a successful upgrade to TLS when speaking to an IMAP, POP3 or FTP server (`--ssl-reqd` on the command line or`CURLOPT_USE_SSL` set to `CURLUSESSL_CONTROL` or `CURLUSESSL_ALL` withlibcurl). This requirement could be bypassed if the server would return a properly crafted but perfectly legitimate response.This flaw would then make curl silently continue its operations
**withoutTLS** contrary to the instructions and expectations, exposing possibly sensitive data in clear text over the network. (CVE-2021-22946)

- When curl >= 7.20.0 and <= 7.78.0 connects to an IMAP or POP3 server to retrieve data using STARTTLS to upgrade to TLS security, the server can respond and send back multiple responses at once that curl caches.
curl would then upgrade to TLS but not flush the in-queue of cached responses but instead continue using and trustingthe responses it got *before* the TLS handshake as if they were authenticated.Using this flaw, it allows a Man-In-The-Middle attacker to first inject the fake responses, then pass-through the TLS traffic from the legitimate server and trick curl into sending data back to the user thinking the attacker's injected data comes from the TLS-protected server. (CVE-2021-22947)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

Solution

Upgrade the curl packages.

For Debian 9 stretch, these problems have been fixed in version 7.52.1-5+deb9u16.

See Also

https://security-tracker.debian.org/tracker/source-package/curl

https://www.debian.org/lts/security/2021/dla-2773

https://security-tracker.debian.org/tracker/CVE-2021-22946

https://security-tracker.debian.org/tracker/CVE-2021-22947

https://packages.debian.org/source/stretch/curl

Plugin Details

Severity: High

ID: 153845

File Name: debian_DLA-2773.nasl

Version: 1.3

Type: local

Agent: unix

Published: 10/3/2021

Updated: 1/20/2022

Supported Sensors: Frictionless Assessment Agent, Nessus Agent

Risk Information

VPR

Risk Factor: Medium

Score: 5.1

CVSS v2

Risk Factor: Medium

Base Score: 5

Temporal Score: 3.7

Vector: AV:N/AC:L/Au:N/C:P/I:N/A:N

Temporal Vector: E:U/RL:OF/RC:C

CVSS Score Source: CVE-2021-22946

CVSS v3

Risk Factor: High

Base Score: 7.5

Temporal Score: 6.5

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Temporal Vector: E:U/RL:O/RC:C

Vulnerability Information

CPE: p-cpe:/a:debian:debian_linux:curl, p-cpe:/a:debian:debian_linux:libcurl3, p-cpe:/a:debian:debian_linux:libcurl3-dbg, p-cpe:/a:debian:debian_linux:libcurl3-gnutls, p-cpe:/a:debian:debian_linux:libcurl3-nss, p-cpe:/a:debian:debian_linux:libcurl4-doc, p-cpe:/a:debian:debian_linux:libcurl4-gnutls-dev, p-cpe:/a:debian:debian_linux:libcurl4-nss-dev, p-cpe:/a:debian:debian_linux:libcurl4-openssl-dev, cpe:/o:debian:debian_linux:9.0

Required KB Items: Host/local_checks_enabled, Host/Debian/release, Host/Debian/dpkg-l

Exploit Ease: No known exploits are available

Patch Publication Date: 9/30/2021

Vulnerability Publication Date: 9/17/2021

Reference Information

CVE: CVE-2021-22946, CVE-2021-22947