Incorrect returning of an error code in the index.c:read_entry() function leads to a double free in libgit2 before v0.26.2, which allows an attacker to cause a denial of service via a crafted repository index file.

The remote Debian 9 host has packages installed that are affected by multiple vulnerabilities as referenced in the dla-2936 advisory.

    Multiple vulnerabilities were found in libgit2, a low-level Git library, and are as follows: CVE-2018-8098     Integer overflow in the index.c:read_entry() function while decompressing a compressed prefix length in     libgit2 before v0.26.2 allows an attacker to cause a denial of service (out-of-bounds read) via a crafted     repository index file. CVE-2018-8099 Incorrect returning of an error code in the index.c:read_entry()     function leads to a double free in libgit2 before v0.26.2, which allows an attacker to cause a denial of     service via a crafted repository index file. CVE-2018-10887 It has been discovered that an unexpected sign     extension in git_delta_apply function in delta-apply.c file may lead to an integer overflow which in turn     leads to an out of bound read, allowing to read before the base object. An attacker may use this flaw to     leak memory addresses or cause a Denial of Service. CVE-2018-10888 A missing check in git_delta_apply     function in delta-apply.c file, may lead to an out-of-bound read while reading a binary delta file. An     attacker may use this flaw to cause a Denial of Service. CVE-2018-15501 In ng_pkt in     transports/smart_pkt.c in libgit2, a remote attacker can send a crafted smart-protocol ng packet that     lacks a '\0' byte to trigger an out-of-bounds read that leads to DoS. CVE-2020-12278 path.c mishandles     equivalent filenames that exist because of NTFS Alternate Data Streams. This may allow remote code     execution when cloning a repository. This issue is similar to CVE-2019-1352. CVE-2020-12279 checkout.c     mishandles equivalent filenames that exist because of NTFS short names. This may allow remote code     execution when cloning a repository. This issue is similar to CVE-2019-1353. For Debian 9 stretch, these     problems have been fixed in version 0.25.1+really0.24.6-1+deb9u1. We recommend that you upgrade your     libgit2 packages. For the detailed security status of libgit2 please refer to its security tracker page     at: https://security-tracker.debian.org/tracker/libgit2 Further information about Debian LTS security     advisories, how to apply these updates to your system and frequently asked questions can be found at:
    https://wiki.debian.org/LTS

Tenable has extracted the preceding description block directly from the Debian security advisory.

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

Update to 0.26.3

Note that Tenable Network Security has extracted the preceding description block directly from the Fedora update system website.
Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

This update for libgit2 fixes the following issues :

  - CVE-2018-8099: Fixed possible denial of service attack     via different vectors by not being able to differentiate     between these status codes (bsc#1085256).

  - CVE-2018-11235: With a crafted .gitmodules file, a     malicious project can execute an arbitrary script on a     machine that runs 'git clone --recurse-submodules'     because submodule 'names' are obtained from this file,     and then appended to $GIT_DIR/modules, leading to     directory traversal with '../' in a name. Finally,     post-checkout hooks from a submodule are executed,     bypassing the intended design in which hooks are not     obtained from a remote server. (bsc#1095219)

  - CVE-2018-10887: It has been discovered that an     unexpected sign extension in git_delta_apply function in     delta.c file may have lead to an integer overflow which     in turn leads to an out of bound read, allowing to read     before the base object. An attacker could have used this     flaw to leak memory addresses or cause a Denial of     Service. (bsc#1100613)

  - CVE-2018-10888: A missing check in git_delta_apply     function in delta.c file, may lead to an out-of-bound     read while reading a binary delta file. An attacker may     use this flaw to cause a Denial of Service.
    (bsc#1100612)

  - CVE-2018-15501: A remote attacker can send a crafted     smart-protocol 'ng' packet that lacks a '\0' byte to     trigger an out-of-bounds read that leads to DoS.
    (bsc#1104641)

This update was imported from the SUSE:SLE-12-SP2:Update update project.

ID	Name	Product	Family	Type	Severity
159090	Debian DLA-2936-1 : libgit2 - LTS security update	Nessus	Debian Local Security Checks	Local	critical
120619	Fedora 28 : libgit2 (2018-924da855e1)	Nessus	Fedora Local Security Checks	Local	medium
118486	openSUSE Security Update : libgit2 (openSUSE-2018-1314)	Nessus	SuSE Local Security Checks	Local	high

Detections

Analytics

CVE-2018-8099

medium

Tenable Plugins

critical

medium

high