{"id":"GHSA-86c2-4x57-wc8g","summary":"Git Credential Manager carriage-return character in remote URL allows malicious repository to leak credentials","details":"### Description\nThe [Git credential protocol](https://git-scm.com/docs/git-credential#IOFMT) is text-based over standard input/output, and consists of a series of lines of key-value pairs in the format `key=value`. Git's documentation restricts the use of the NUL (`\\0`) character and newlines to form part of the keys[^1] or values.\n\nWhen Git reads from standard input, it considers both LF and CRLF[^2] as newline characters for the credential protocol by virtue of [calling `strbuf_getline`](https://github.com/git/git/blob/6a11438f43469f3815f2f0fc997bd45792ff04c0/credential.c#L311) that calls to `strbuf_getdelim_strip_crlf`. Git also validates that a newline is not present in the value by checking for the presence of the line-feed character (LF, `\\n`), and errors if this is the case. This captures both LF and CRLF-type newlines.\n\nGit Credential Manager uses the .NET standard library [`StreamReader`](https://learn.microsoft.com/en-us/dotnet/api/system.io.streamreader?view=net-8.0) class to [read the standard input stream line-by-line](https://github.com/git-ecosystem/git-credential-manager/blob/ae009e11a0fbef804ad9f78816d84a0bc7e052fe/src/shared/Core/StreamExtensions.cs#L138-L141) and parse the `key=value` credential protocol format. The [implementation of the `ReadLineAsync` method](https://github.com/dotnet/runtime/blob/e476b43b5cb42eb44ce23b1c7b793aa361624cf6/src/libraries/System.Private.CoreLib/src/System/IO/StreamReader.cs#L926) considers LF, CRLF, and CR as valid line endings. This is means that .NET considers a single CR as a valid newline character, whereas Git does not.\n\nThis mismatch of newline treatment between Git and GCM means that an attacker can craft a malicious remote URL such as:\n\n```\nhttps://\\rhost=targethost@badhost\n```\n\n..which will be interpreted by Git as:\n\n```\nprotocol=https\nhost=badhost\nusername=\\rhost=targethost\n```\n\nThis will instead be parsed by GCM as if the following has been passed by Git:\n\n```\nprotocol=https\nhost=badhost\nusername=\nhost=targethost\n```\n\nThis results in the `host` field being resolved to the `targethost` value. GCM will then return a credential for `targethost` to Git, which will then send this credential to the `badhost` host.\n\n### Impact\nWhen a user clones or otherwise interacts[^3] with a malicious repository that requires authentication, the attacker can capture credentials for another Git remote. The attack is also heightened when cloning from repositories with submodules when using the `--recursive` clone option as the user is not able to inspect the submodule remote URLs beforehand.\n\n### Patches\nhttps://github.com/git-ecosystem/git-credential-manager/compare/749e287571c78a2b61f926ccce6a707050871ab8...99e2f7f60e7364fe807e7925f361a81f3c47bd1b\n\n### Workarounds\nOnly interacting with trusted remote repositories, and do not clone with `--recursive` to allow inspection of any submodule URLs before cloning those submodules.\n\n### Fixed versions\nThis issue is fixed as of [version 2.6.1](https://github.com/git-ecosystem/git-credential-manager/releases/tag/v2.6.1).\n\n[^1]: The `=` character is also forbidden to form part of the key.\n[^2]: Carriage-return character (CR, `\\r`), followed by a line-feed character.\n[^3]: Any remote operation such as `fetch`, `ls-remote`, etc.","aliases":["CVE-2024-50338"],"modified":"2026-01-30T00:56:44.958701Z","published":"2025-01-14T19:40:54Z","related":["CVE-2024-52006"],"database_specific":{"github_reviewed_at":"2025-01-14T19:40:54Z","nvd_published_at":"2025-01-14T19:15:31Z","cwe_ids":["CWE-200","CWE-436"],"severity":"HIGH","github_reviewed":true},"references":[{"type":"WEB","url":"https://github.com/git-ecosystem/git-credential-manager/security/advisories/GHSA-86c2-4x57-wc8g"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2024-50338"},{"type":"WEB","url":"https://git-scm.com/docs/git-credential#IOFMT"},{"type":"WEB","url":"https://github.com/dotnet/runtime/blob/e476b43b5cb42eb44ce23b1c7b793aa361624cf6/src/libraries/System.Private.CoreLib/src/System/IO/StreamReader.cs#L926"},{"type":"PACKAGE","url":"https://github.com/git-ecosystem/git-credential-manager"},{"type":"WEB","url":"https://github.com/git-ecosystem/git-credential-manager/blob/ae009e11a0fbef804ad9f78816d84a0bc7e052fe/src/shared/Core/StreamExtensions.cs#L138-L141"},{"type":"WEB","url":"https://github.com/git-ecosystem/git-credential-manager/compare/749e287571c78a2b61f926ccce6a707050871ab8...99e2f7f60e7364fe807e7925f361a81f3c47bd1b"},{"type":"WEB","url":"https://github.com/git-ecosystem/git-credential-manager/releases/tag/v2.6.1"},{"type":"WEB","url":"https://github.com/git/git/blob/6a11438f43469f3815f2f0fc997bd45792ff04c0/credential.c#L311"},{"type":"WEB","url":"https://learn.microsoft.com/en-us/dotnet/api/system.io.streamreader?view=net-8.0"}],"affected":[{"package":{"name":"git-credential-manager","ecosystem":"NuGet","purl":"pkg:nuget/git-credential-manager"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.6.1"}]}],"versions":["0.1.0","2.0.798-gd247513b19","2.0.866","2.0.877","2.0.886","2.0.931","2.0.935","2.1.0","2.1.1","2.1.2","2.2.1","2.2.2","2.3.0","2.3.1","2.3.2","2.4.1","2.5.1","2.6.0"],"database_specific":{"last_known_affected_version_range":"\u003c= 2.6.0","source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2025/01/GHSA-86c2-4x57-wc8g/GHSA-86c2-4x57-wc8g.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:N/A:N"}]}